Add dedicated self-contained publish helpers

Add backend and client self-contained publish scripts that clean the public output folders and publish Release win-x64 builds with the .NET runtime included for easier deployment.

Api/ApiDtoMapper.cs

@@ -0,0 +1,149 @@
+using UtopiaCanteen.Shared;
+using UtopiaCanteenSystem.Models;
+using UtopiaCanteenSystem.Services;
+
+namespace UtopiaCanteenSystem.Api;
+
+public static class ApiDtoMapper
+{
+    public static EmployeeDto? ToEmployeeDto(HrmsEmployeeInfo? e)
+    {
+        if (e == null) return null;
+        return new EmployeeDto
+        {
+            ParentDocumentId = e.ParentDocumentId,
+            EmployeeId = e.EmployeeId,
+            UindSerial = e.UindSerial,
+            FunctionId = e.FunctionId,
+            DepartmentId = e.DepartmentId,
+            TagCreatedAtUtc = e.TagCreatedAtUtc,
+            TagCreatedBy = e.TagCreatedBy,
+            FirstName = e.FirstName,
+            MiddleName = e.MiddleName,
+            DepartmentTitle = e.DepartmentTitle,
+            DepartmentType = e.DepartmentType,
+            LocationSiteId = e.LocationSiteId,
+            GradeType = e.GradeType
+        };
+    }
+
+    public static HrmsEmployeeInfo ToModel(EmployeeDto e) => new()
+    {
+        ParentDocumentId = e.ParentDocumentId ?? string.Empty,
+        EmployeeId = e.EmployeeId ?? string.Empty,
+        UindSerial = e.UindSerial ?? string.Empty,
+        FunctionId = e.FunctionId,
+        DepartmentId = e.DepartmentId,
+        TagCreatedAtUtc = e.TagCreatedAtUtc,
+        TagCreatedBy = e.TagCreatedBy ?? string.Empty,
+        FirstName = e.FirstName ?? string.Empty,
+        MiddleName = e.MiddleName ?? string.Empty,
+        DepartmentTitle = e.DepartmentTitle ?? string.Empty,
+        DepartmentType = e.DepartmentType ?? string.Empty,
+        LocationSiteId = e.LocationSiteId ?? string.Empty,
+        GradeType = e.GradeType ?? string.Empty
+    };
+
+    public static ScanResponse ToScanResponse(ScanResult r, string? mealLabel = null, string? mealItems = null, double totalPrice = 0) =>
+        new()
+        {
+            Success = r.Success,
+            Message = r.Message,
+            CooldownSecondsRemaining = r.CooldownSecondsRemaining,
+            Employee = ToEmployeeDto(r.EmployeeInfo),
+            MealSession = (int)r.MealSession,
+            EmployeeSiteId = r.EmployeeSiteId,
+            CurrentSiteId = r.CurrentSiteId,
+            MealLabel = mealLabel,
+            MealItems = mealItems,
+            TotalPrice = totalPrice
+        };
+
+    public static RecentScanDto ToRecentScanDto(ScanRecord r) => new()
+    {
+        Id = r.Id,
+        CardId = r.CardId,
+        ScanTime = r.ScanTime,
+        IsSynced = r.IsSynced,
+        SiteId = r.SiteId,
+        DeviceId = r.DeviceId,
+        IpAddress = r.IpAddress,
+        MealSessionCode = r.MealSessionCode,
+        ParentDocumentId = r.ParentDocumentId,
+        EmployeeId = r.EmployeeId,
+        UindSerial = r.UindSerial,
+        FunctionId = r.FunctionId,
+        DepartmentId = r.DepartmentId,
+        TagCreatedAtUtc = r.TagCreatedAtUtc,
+        TagCreatedBy = r.TagCreatedBy,
+        EmployeeName = r.EmployeeName,
+        Department = r.Department,
+        DepartmentType = r.DepartmentType,
+        MealLabel = r.MealLabel,
+        MealItems = r.MealItems,
+        TotalPrice = r.TotalPrice,
+        GradeType = r.grade_type
+    };
+
+    public static ScanRecord ToEntity(RecentScanDto d) => new()
+    {
+        Id = d.Id,
+        CardId = d.CardId ?? string.Empty,
+        ScanTime = d.ScanTime,
+        IsSynced = d.IsSynced,
+        SiteId = d.SiteId ?? string.Empty,
+        DeviceId = d.DeviceId ?? string.Empty,
+        IpAddress = d.IpAddress ?? string.Empty,
+        MealSessionCode = d.MealSessionCode,
+        ParentDocumentId = d.ParentDocumentId ?? string.Empty,
+        EmployeeId = d.EmployeeId ?? string.Empty,
+        UindSerial = d.UindSerial ?? string.Empty,
+        FunctionId = d.FunctionId,
+        DepartmentId = d.DepartmentId,
+        TagCreatedAtUtc = d.TagCreatedAtUtc,
+        TagCreatedBy = d.TagCreatedBy ?? string.Empty,
+        EmployeeName = d.EmployeeName ?? string.Empty,
+        Department = d.Department ?? string.Empty,
+        DepartmentType = d.DepartmentType ?? string.Empty,
+        MealLabel = d.MealLabel ?? string.Empty,
+        MealItems = d.MealItems ?? string.Empty,
+        TotalPrice = d.TotalPrice,
+        grade_type = d.GradeType ?? string.Empty
+    };
+
+    public static ManualSyncResponse ToManualSync(bool success, string message, DateTime? started, DateTime? completed, string? details = null) =>
+        new()
+        {
+            Success = success,
+            Message = message,
+            StartedAt = started,
+            CompletedAt = completed,
+            Details = details
+        };
+
+    public static MealScheduleDto ToMealScheduleDto(MealSchedule s) => new()
+    {
+        Id = s.Id,
+        MealName = s.MealName,
+        LocationSiteId = s.LocationSiteId,
+        MealSession = s.MealSession,
+        StartTime = s.StartTime,
+        EndTime = s.EndTime,
+        IsActive = s.IsActive,
+        CreatedAt = s.CreatedAt,
+        UpdatedAt = s.UpdatedAt
+    };
+
+    public static MealSchedule ToMealSchedule(MealScheduleDto d) => new()
+    {
+        Id = d.Id,
+        MealName = d.MealName ?? string.Empty,
+        LocationSiteId = d.LocationSiteId ?? string.Empty,
+        MealSession = d.MealSession,
+        StartTime = d.StartTime ?? string.Empty,
+        EndTime = d.EndTime ?? string.Empty,
+        IsActive = d.IsActive,
+        CreatedAt = d.CreatedAt,
+        UpdatedAt = d.UpdatedAt
+    };
+}

Api/BackendApiDtos.cs

@@ -0,0 +1,23 @@
+namespace UtopiaCanteenSystem.Api;
+
+public sealed class HealthResponseDto
+{
+    public string Status { get; set; } = "ok";
+    public string Mode { get; set; } = "server";
+    public DateTime Utc { get; set; }
+}
+
+public sealed class BackendJobResponseDto
+{
+    public bool Success { get; set; }
+    public string Message { get; set; } = string.Empty;
+    public DateTime? StartedAt { get; set; }
+    public DateTime? CompletedAt { get; set; }
+    public string? Details { get; set; }
+}
+
+public sealed class CacheStatusResponseDto
+{
+    public DateTime? LastEmployeeRfidCacheSyncUtc { get; set; }
+    public DateTime? LastMealMenuCacheSyncUtc { get; set; }
+}

Api/CanteenBackendHost.cs

@@ -0,0 +1,567 @@
+using System.IO;
+using System.Net;
+using System.Text;
+using System.Text.Json;
+using Microsoft.EntityFrameworkCore;
+using UtopiaCanteen.Shared;
+using UtopiaCanteenSystem.Data;
+using UtopiaCanteenSystem.Models;
+using UtopiaCanteenSystem.Services;
+using UtopiaCanteenSystem.Services.Logging;
+
+namespace UtopiaCanteenSystem.Api;
+
+/// <summary>
+/// Central server HTTP API (backend). Scanner and settings UIs call this; only this layer touches SQLite and HRMS.
+/// </summary>
+public static class CanteenBackendHost
+{
+    private static readonly JsonSerializerOptions JsonOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        PropertyNameCaseInsensitive = true
+    };
+
+    public static async Task RunAsync(CanteenBackendServices backend, string listenUrls, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(listenUrls))
+            listenUrls = "http://0.0.0.0:5000/";
+
+        var prefixes = listenUrls
+            .Split(new[] { ';', ',' }, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
+            .Select(NormalizePrefix)
+            .Where(p => !string.IsNullOrEmpty(p))
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+
+        if (prefixes.Length == 0)
+            prefixes = new[] { "http://+:5000/" };
+
+        using var listener = new HttpListener();
+        foreach (var prefix in prefixes)
+            listener.Prefixes.Add(prefix);
+
+        listener.Start();
+        FileLogger.Info("BackendHost", $"Listening on {string.Join(", ", prefixes)}");
+
+        try
+        {
+            while (!cancellationToken.IsCancellationRequested)
+            {
+                HttpListenerContext ctx;
+                try
+                {
+                    ctx = await listener.GetContextAsync().ConfigureAwait(false);
+                }
+                catch (HttpListenerException) when (cancellationToken.IsCancellationRequested)
+                {
+                    break;
+                }
+                catch (ObjectDisposedException)
+                {
+                    break;
+                }
+
+                _ = Task.Run(() => ProcessRequestAsync(ctx, backend), cancellationToken);
+            }
+        }
+        finally
+        {
+            listener.Stop();
+            listener.Close();
+        }
+    }
+
+    private static async Task ProcessRequestAsync(HttpListenerContext ctx, CanteenBackendServices backend)
+    {
+        try
+        {
+            AddCorsHeaders(ctx.Response);
+            if (string.Equals(ctx.Request.HttpMethod, "OPTIONS", StringComparison.OrdinalIgnoreCase))
+            {
+                ctx.Response.StatusCode = 204;
+                ctx.Response.Close();
+                return;
+            }
+
+            var path = ctx.Request.Url?.AbsolutePath?.TrimEnd('/') ?? string.Empty;
+            var method = ctx.Request.HttpMethod ?? "GET";
+            var clientIp = GetClientIp(ctx);
+            var rfid = backend.Rfid;
+
+            FileLogger.Info("BackendHost", $"{method} {path} from {clientIp}");
+
+            if (method == "GET" && path.Equals("/api/health", StringComparison.OrdinalIgnoreCase))
+            {
+                FileLogger.Debug("BackendHost", "Health check OK.");
+                await WriteJsonAsync(ctx, new HealthResponse
+                {
+                    Status = "ok",
+                    Mode = "server",
+                    Utc = DateTime.UtcNow
+                }).ConfigureAwait(false);
+                return;
+            }
+
+            if (method == "GET" && path.Equals("/api/logs/path", StringComparison.OrdinalIgnoreCase))
+            {
+                await WriteJsonAsync(ctx, new { logsPath = LogPaths.BackendLogsDirectory }).ConfigureAwait(false);
+                return;
+            }
+
+            if (method == "POST" && path.Equals("/api/rfid/scan", StringComparison.OrdinalIgnoreCase))
+            {
+                await HandleScanAsync(ctx, rfid, backend).ConfigureAwait(false);
+                return;
+            }
+
+            if (method == "POST" && path.Equals("/api/cache/sync-now", StringComparison.OrdinalIgnoreCase))
+            {
+                await HandleCacheSyncAsync(ctx, backend).ConfigureAwait(false);
+                return;
+            }
+
+            if (method == "POST" && path.Equals("/api/orders/sync-now", StringComparison.OrdinalIgnoreCase))
+            {
+                await HandleOrdersSyncAsync(ctx, backend).ConfigureAwait(false);
+                return;
+            }
+
+            if (path.StartsWith("/api/meal-schedules", StringComparison.OrdinalIgnoreCase))
+            {
+                await HandleMealSchedulesAsync(ctx, backend, path, method).ConfigureAwait(false);
+                return;
+            }
+
+            if (method == "GET")
+            {
+                if (path.Equals("/api/cache/status", StringComparison.OrdinalIgnoreCase))
+                {
+                    await WriteJsonAsync(ctx, new CacheStatusResponse
+                    {
+                        LastEmployeeRfidCacheSyncUtc = backend.Config.GetLastEmployeeRfidCacheSyncUtc(),
+                        LastMealMenuCacheSyncUtc = backend.Config.GetLastMealMenuCacheSyncUtc()
+                    }).ConfigureAwait(false);
+                    return;
+                }
+
+                if (path.Equals("/api/rfid/scans/today", StringComparison.OrdinalIgnoreCase))
+                {
+                    await WriteJsonAsync(ctx, rfid.GetScansForToday().Select(ApiDtoMapper.ToRecentScanDto).ToList()).ConfigureAwait(false);
+                    return;
+                }
+
+                if (path.Equals("/api/rfid/scans/last", StringComparison.OrdinalIgnoreCase))
+                {
+                    var last = rfid.GetLastScan();
+                    await WriteJsonAsync(ctx, last == null ? null : ApiDtoMapper.ToRecentScanDto(last)).ConfigureAwait(false);
+                    return;
+                }
+
+                if (path.StartsWith("/api/rfid/scans/recent", StringComparison.OrdinalIgnoreCase))
+                {
+                    var count = ParseQueryInt(ctx.Request.Url?.Query, "count", 4);
+                    var list = rfid.GetLastScans(count).Select(ApiDtoMapper.ToRecentScanDto).ToList();
+                    await WriteJsonAsync(ctx, list).ConfigureAwait(false);
+                    return;
+                }
+
+                if (path.Equals("/api/rfid/stats/today", StringComparison.OrdinalIgnoreCase))
+                {
+                    var n = await rfid.GetTodayScanCountAsync().ConfigureAwait(false);
+                    await WriteJsonAsync(ctx, new StatsDto { Count = n }).ConfigureAwait(false);
+                    return;
+                }
+
+                if (path.Equals("/api/rfid/stats/total", StringComparison.OrdinalIgnoreCase))
+                {
+                    var n = await rfid.GetTotalScanCountAsync().ConfigureAwait(false);
+                    await WriteJsonAsync(ctx, new StatsDto { Count = n }).ConfigureAwait(false);
+                    return;
+                }
+
+                if (path.StartsWith("/api/rfid/stats/today-for-card", StringComparison.OrdinalIgnoreCase))
+                {
+                    var cardId = ParseQueryString(ctx.Request.Url?.Query, "cardId");
+                    var n = await rfid.GetTodayScanCountForCardAsync(cardId ?? string.Empty).ConfigureAwait(false);
+                    await WriteJsonAsync(ctx, new StatsDto { Count = n }).ConfigureAwait(false);
+                    return;
+                }
+
+                if (path.StartsWith("/api/rfid/stats/total-for-card", StringComparison.OrdinalIgnoreCase))
+                {
+                    var cardId = ParseQueryString(ctx.Request.Url?.Query, "cardId");
+                    var n = await rfid.GetTotalScanCountForCardAsync(cardId ?? string.Empty).ConfigureAwait(false);
+                    await WriteJsonAsync(ctx, new StatsDto { Count = n }).ConfigureAwait(false);
+                    return;
+                }
+
+                if (path.Equals("/api/employees/location-site", StringComparison.OrdinalIgnoreCase))
+                {
+                    await HandleEmployeeLocationSiteAsync(ctx).ConfigureAwait(false);
+                    return;
+                }
+            }
+
+            await WriteJsonAsync(ctx, new { message = "Not found" }, 404).ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "CanteenBackendHost.ProcessRequestAsync");
+            try
+            {
+                await WriteJsonAsync(ctx, new { message = ex.Message }, 500).ConfigureAwait(false);
+            }
+            catch
+            {
+                // Ignore
+            }
+        }
+    }
+
+    private static async Task HandleCacheSyncAsync(HttpListenerContext ctx, CanteenBackendServices backend)
+    {
+        var started = DateTime.UtcNow;
+        FileLogger.Info("CacheSync", "Manual cache sync API request received (POST /api/cache/sync-now).");
+        try
+        {
+            var result = await backend.RunCacheSyncExclusiveAsync(async () =>
+            {
+                if (string.IsNullOrWhiteSpace(backend.Config.GetHrmsLookupConnectionString()))
+                {
+                    FileLogger.Warn("CacheSync", "Manual cache sync failed. MySQL connection string is not configured.");
+                    return ApiDtoMapper.ToManualSync(false, "MySQL connection string is not configured.", started, DateTime.UtcNow);
+                }
+
+                var sync = await backend.OfflineCacheSync.SyncEmployeeAndMenuCacheAsync().ConfigureAwait(false);
+                var completed = DateTime.UtcNow;
+                if (!sync.Success)
+                {
+                    FileLogger.Error("CacheSync", $"Manual cache sync failed. Error={sync.ErrorMessage}");
+                    return ApiDtoMapper.ToManualSync(false, sync.ErrorMessage ?? "Cache sync failed.", started, completed, sync.ErrorMessage);
+                }
+
+                var emp = sync.EmployeeSync?.UpsertedCount ?? 0;
+                var meal = sync.MealMenuSync;
+                var details =
+                    $"Employee RFID tags: {emp}; " +
+                    $"Meal schedules: {meal?.MealScheduleCount ?? 0}; " +
+                    $"Menu weeks: {meal?.LunchMenuWeekCount ?? 0}; " +
+                    $"Menu items: {meal?.LunchMenuItemCount ?? 0}; " +
+                    $"Menu catalog: {meal?.MenuItemCount ?? 0}.";
+
+                FileLogger.Info("CacheSync", $"Manual cache sync completed successfully. {details}");
+                return ApiDtoMapper.ToManualSync(true, "Employee and menu cache synced successfully.", started, completed, details);
+            }).ConfigureAwait(false);
+
+            FileLogger.Info("CacheSync", $"Cache sync API response. Success={result.Success}, Message={result.Message}");
+            await WriteJsonAsync(ctx, result, result.Success ? 200 : 500).ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "CanteenBackendHost.HandleCacheSyncAsync");
+            FileLogger.Error("CacheSync", "Manual cache sync API failed with exception.", ex);
+            await WriteJsonAsync(ctx, ApiDtoMapper.ToManualSync(false, ex.Message, started, DateTime.UtcNow, ex.ToString()), 500).ConfigureAwait(false);
+        }
+    }
+
+    private static async Task HandleOrdersSyncAsync(HttpListenerContext ctx, CanteenBackendServices backend)
+    {
+        var started = DateTime.UtcNow;
+        FileLogger.Info("OrderSync", "Manual order sync API request received (POST /api/orders/sync-now).");
+        try
+        {
+            var result = await backend.RunOrderSyncExclusiveAsync(async () =>
+            {
+                if (string.IsNullOrWhiteSpace(backend.Config.GetMySqlConnectionString()))
+                {
+                    FileLogger.Warn("OrderSync", "Manual order sync failed. Production MySQL connection is not configured.");
+                    return ApiDtoMapper.ToManualSync(false, "Production MySQL connection is not configured.", started, DateTime.UtcNow);
+                }
+
+                var stats = await backend.ProductionSync.SyncNowAsync().ConfigureAwait(false);
+                var completed = DateTime.UtcNow;
+                var details =
+                    $"Pending={stats.PendingCount}, Posted={stats.PostedCount}, " +
+                    $"DuplicatesSkipped={stats.DuplicatesSkippedCount}, Failed={stats.FailedCount}.";
+                var success = !stats.SkippedNoConnection && stats.FailedCount == 0;
+                var message = stats.PendingCount == 0
+                    ? "No pending orders to post."
+                    : success
+                        ? "Pending orders posted to production."
+                        : "Order sync completed with errors.";
+
+                if (success)
+                    FileLogger.Info("OrderSync", $"Manual order sync completed. {details}");
+                else
+                    FileLogger.Warn("OrderSync", $"Manual order sync finished with issues. {details}");
+
+                return ApiDtoMapper.ToManualSync(success, message, started, completed, details);
+            }).ConfigureAwait(false);
+
+            FileLogger.Info("OrderSync", $"Order sync API response. Success={result.Success}, Message={result.Message}");
+            await WriteJsonAsync(ctx, result, result.Success ? 200 : 500).ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "CanteenBackendHost.HandleOrdersSyncAsync");
+            FileLogger.Error("OrderSync", "Manual order sync API failed with exception.", ex);
+            await WriteJsonAsync(ctx, ApiDtoMapper.ToManualSync(false, ex.Message, started, DateTime.UtcNow, ex.ToString()), 500).ConfigureAwait(false);
+        }
+    }
+
+    private static async Task HandleScanAsync(HttpListenerContext ctx, RfidService rfid, CanteenBackendServices backend)
+    {
+        ScanRequest? dto;
+        using (var reader = new StreamReader(ctx.Request.InputStream, ctx.Request.ContentEncoding))
+        {
+            var body = await reader.ReadToEndAsync().ConfigureAwait(false);
+            if (string.IsNullOrWhiteSpace(body))
+            {
+                await WriteJsonAsync(ctx, new { message = "Request body required." }, 400).ConfigureAwait(false);
+                return;
+            }
+
+            dto = JsonSerializer.Deserialize<ScanRequest>(body, JsonOptions);
+        }
+
+        if (dto == null || string.IsNullOrWhiteSpace(dto.CardId))
+        {
+            await WriteJsonAsync(ctx, new { message = "cardId is required." }, 400).ConfigureAwait(false);
+            return;
+        }
+
+        var remoteIp = ctx.Request.RemoteEndPoint?.Address?.ToString() ?? string.Empty;
+        if (remoteIp == "::1")
+            remoteIp = "127.0.0.1";
+
+        var ip = string.IsNullOrWhiteSpace(dto.IpAddress) ? remoteIp : dto.IpAddress!.Trim();
+
+        var clientCtx = new RfidScanClientContext
+        {
+            DeviceId = string.IsNullOrWhiteSpace(dto.DeviceId)
+                ? backend.Config.GetDeviceId()
+                : dto.DeviceId.Trim(),
+            SiteId = dto.SiteId?.Trim() ?? string.Empty,
+            IpAddress = ip
+        };
+
+        FileLogger.Info(
+            "RfidScan",
+            $"Scan request. CardId={LogMasking.MaskCardId(dto.CardId)}, DeviceId={clientCtx.DeviceId}, SiteId={clientCtx.SiteId}, ClientIp={remoteIp}");
+
+        var result = rfid.ProcessScanDetailed(dto.CardId.Trim(), clientCtx);
+
+        var duplicateBlocked = !result.Success &&
+            (result.Message.Contains("already", StringComparison.OrdinalIgnoreCase) ||
+             result.Message.Contains("within", StringComparison.OrdinalIgnoreCase));
+        FileLogger.Info(
+            "RfidScan",
+            $"Scan result. Success={result.Success}, Message={result.Message}, DuplicateBlocked={duplicateBlocked}, OrderSaved={result.Success}");
+
+        string? mealLabel = null;
+        string? mealItems = null;
+        double totalPrice = 0;
+        if (result.Success)
+        {
+            var last = rfid.GetLastScan();
+            if (last != null)
+            {
+                mealLabel = last.MealLabel;
+                mealItems = last.MealItems;
+                totalPrice = last.TotalPrice;
+            }
+        }
+
+        var response = ApiDtoMapper.ToScanResponse(result, mealLabel, mealItems, totalPrice);
+        await WriteJsonAsync(ctx, response).ConfigureAwait(false);
+    }
+
+    private static void AddCorsHeaders(HttpListenerResponse response)
+    {
+        response.Headers.Add("Access-Control-Allow-Origin", "*");
+        response.Headers.Add("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS");
+        response.Headers.Add("Access-Control-Allow-Headers", "Content-Type");
+    }
+
+    private static async Task WriteJsonAsync(HttpListenerContext ctx, object? payload, int statusCode = 200)
+    {
+        var json = JsonSerializer.Serialize(payload, JsonOptions);
+        var bytes = Encoding.UTF8.GetBytes(json);
+        ctx.Response.StatusCode = statusCode;
+        ctx.Response.ContentType = "application/json; charset=utf-8";
+        ctx.Response.ContentLength64 = bytes.Length;
+        AddCorsHeaders(ctx.Response);
+        await ctx.Response.OutputStream.WriteAsync(bytes).ConfigureAwait(false);
+        ctx.Response.Close();
+    }
+
+    private static async Task HandleEmployeeLocationSiteAsync(HttpListenerContext ctx)
+    {
+        var employeeId = ParseQueryString(ctx.Request.Url?.Query, "employeeId")?.Trim() ?? string.Empty;
+        if (string.IsNullOrEmpty(employeeId))
+        {
+            await WriteJsonAsync(ctx, new EmployeeLocationSiteResponse(), 400).ConfigureAwait(false);
+            return;
+        }
+
+        try
+        {
+            var dbFactory = new DbContextFactory();
+            await using var db = dbFactory.CreateDbContext();
+            var siteId = await db.EmployeeRfidTagCache
+                .AsNoTracking()
+                .Where(x => x.ParentDocumentType == "Employee")
+                .Where(x => x.EmployeeSerialNumber == employeeId)
+                .Where(x => !string.IsNullOrEmpty(x.LocationSiteId))
+                .Select(x => x.LocationSiteId)
+                .FirstOrDefaultAsync()
+                .ConfigureAwait(false);
+
+            await WriteJsonAsync(ctx, new EmployeeLocationSiteResponse
+            {
+                LocationSiteId = string.IsNullOrWhiteSpace(siteId) ? null : siteId.Trim()
+            }).ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "CanteenBackendHost.HandleEmployeeLocationSiteAsync");
+            await WriteJsonAsync(ctx, new EmployeeLocationSiteResponse(), 500).ConfigureAwait(false);
+        }
+    }
+
+    private static async Task HandleMealSchedulesAsync(HttpListenerContext ctx, CanteenBackendServices backend, string path, string method)
+    {
+        var mealSvc = new ProductionMealScheduleService(backend.Config);
+
+        if (method == "GET" && path.Equals("/api/meal-schedules", StringComparison.OrdinalIgnoreCase))
+        {
+            var list = await mealSvc.GetAllSchedulesAsync().ConfigureAwait(false);
+            await WriteJsonAsync(ctx, list.Select(ApiDtoMapper.ToMealScheduleDto).ToList()).ConfigureAwait(false);
+            return;
+        }
+
+        if (method == "POST" && path.Equals("/api/meal-schedules", StringComparison.OrdinalIgnoreCase))
+        {
+            var dto = await ReadJsonBodyAsync<MealScheduleDto>(ctx).ConfigureAwait(false);
+            if (dto == null)
+            {
+                await WriteJsonAsync(ctx, new { message = "Request body required." }, 400).ConfigureAwait(false);
+                return;
+            }
+
+            try
+            {
+                var entity = ApiDtoMapper.ToMealSchedule(dto);
+                var id = await mealSvc.CreateAsync(entity).ConfigureAwait(false);
+                entity.Id = id;
+                await WriteJsonAsync(ctx, ApiDtoMapper.ToMealScheduleDto(entity), 201).ConfigureAwait(false);
+            }
+            catch (Exception ex)
+            {
+                Logger.Log(ex, "CanteenBackendHost.CreateMealSchedule");
+                await WriteJsonAsync(ctx, new { message = ex.Message }, 500).ConfigureAwait(false);
+            }
+            return;
+        }
+
+        var scheduleId = TryParseMealScheduleId(path);
+        if (scheduleId.HasValue)
+        {
+            if (method == "PUT")
+            {
+                var dto = await ReadJsonBodyAsync<MealScheduleDto>(ctx).ConfigureAwait(false);
+                if (dto == null)
+                {
+                    await WriteJsonAsync(ctx, new { message = "Request body required." }, 400).ConfigureAwait(false);
+                    return;
+                }
+
+                try
+                {
+                    var entity = ApiDtoMapper.ToMealSchedule(dto);
+                    entity.Id = scheduleId.Value;
+                    await mealSvc.UpdateAsync(entity).ConfigureAwait(false);
+                    await WriteJsonAsync(ctx, ApiDtoMapper.ToMealScheduleDto(entity)).ConfigureAwait(false);
+                }
+                catch (Exception ex)
+                {
+                    Logger.Log(ex, "CanteenBackendHost.UpdateMealSchedule");
+                    await WriteJsonAsync(ctx, new { message = ex.Message }, 500).ConfigureAwait(false);
+                }
+                return;
+            }
+
+            if (method == "DELETE")
+            {
+                try
+                {
+                    await mealSvc.DeleteAsync(scheduleId.Value).ConfigureAwait(false);
+                    await WriteJsonAsync(ctx, new { success = true }).ConfigureAwait(false);
+                }
+                catch (Exception ex)
+                {
+                    Logger.Log(ex, "CanteenBackendHost.DeleteMealSchedule");
+                    await WriteJsonAsync(ctx, new { message = ex.Message }, 500).ConfigureAwait(false);
+                }
+                return;
+            }
+        }
+
+        await WriteJsonAsync(ctx, new { message = "Not found" }, 404).ConfigureAwait(false);
+    }
+
+    private static long? TryParseMealScheduleId(string path)
+    {
+        const string prefix = "/api/meal-schedules/";
+        if (!path.StartsWith(prefix, StringComparison.OrdinalIgnoreCase))
+            return null;
+        var idPart = path[prefix.Length..];
+        return long.TryParse(idPart, out var id) ? id : null;
+    }
+
+    private static async Task<T?> ReadJsonBodyAsync<T>(HttpListenerContext ctx) where T : class
+    {
+        using var reader = new StreamReader(ctx.Request.InputStream, ctx.Request.ContentEncoding);
+        var body = await reader.ReadToEndAsync().ConfigureAwait(false);
+        if (string.IsNullOrWhiteSpace(body))
+            return null;
+        return JsonSerializer.Deserialize<T>(body, JsonOptions);
+    }
+
+    private static string NormalizePrefix(string url)
+    {
+        var u = url.Trim();
+        if (!u.EndsWith('/'))
+            u += "/";
+        if (u.Contains("0.0.0.0", StringComparison.Ordinal))
+            u = u.Replace("0.0.0.0", "+", StringComparison.Ordinal);
+        return u;
+    }
+
+    private static int ParseQueryInt(string? query, string key, int defaultValue)
+    {
+        var s = ParseQueryString(query, key);
+        return int.TryParse(s, out var n) ? n : defaultValue;
+    }
+
+    private static string GetClientIp(HttpListenerContext ctx)
+    {
+        var ip = ctx.Request.RemoteEndPoint?.Address?.ToString() ?? "unknown";
+        return ip == "::1" ? "127.0.0.1" : ip;
+    }
+
+    private static string? ParseQueryString(string? query, string key)
+    {
+        if (string.IsNullOrEmpty(query))
+            return null;
+        var q = query.TrimStart('?');
+        foreach (var part in q.Split('&', StringSplitOptions.RemoveEmptyEntries))
+        {
+            var kv = part.Split('=', 2);
+            if (kv.Length > 0 && string.Equals(Uri.UnescapeDataString(kv[0]), key, StringComparison.OrdinalIgnoreCase))
+                return kv.Length > 1 ? Uri.UnescapeDataString(kv[1]) : string.Empty;
+        }
+        return null;
+    }
+}

Api/RfidApiDtos.cs

@@ -0,0 +1,178 @@
+using System.Text.Json.Serialization;
+using UtopiaCanteenSystem.Models;
+using UtopiaCanteenSystem.Services;
+
+namespace UtopiaCanteenSystem.Api;
+
+public sealed class RfidScanRequestDto
+{
+    public string CardId { get; set; } = string.Empty;
+    public string DeviceId { get; set; } = string.Empty;
+    public string SiteId { get; set; } = string.Empty;
+    public string? IpAddress { get; set; }
+}
+
+public sealed class HrmsEmployeeInfoDto
+{
+    public string ParentDocumentId { get; set; } = string.Empty;
+    public string EmployeeId { get; set; } = string.Empty;
+    public string UindSerial { get; set; } = string.Empty;
+    public int FunctionId { get; set; }
+    public int DepartmentId { get; set; }
+    public DateTime? TagCreatedAtUtc { get; set; }
+    public string TagCreatedBy { get; set; } = string.Empty;
+    public string FirstName { get; set; } = string.Empty;
+    public string MiddleName { get; set; } = string.Empty;
+    public string DepartmentTitle { get; set; } = string.Empty;
+    public string DepartmentType { get; set; } = string.Empty;
+    public string LocationSiteId { get; set; } = string.Empty;
+    public string GradeType { get; set; } = string.Empty;
+
+    public static HrmsEmployeeInfoDto? FromModel(HrmsEmployeeInfo? e)
+    {
+        if (e == null) return null;
+        return new HrmsEmployeeInfoDto
+        {
+            ParentDocumentId = e.ParentDocumentId,
+            EmployeeId = e.EmployeeId,
+            UindSerial = e.UindSerial,
+            FunctionId = e.FunctionId,
+            DepartmentId = e.DepartmentId,
+            TagCreatedAtUtc = e.TagCreatedAtUtc,
+            TagCreatedBy = e.TagCreatedBy,
+            FirstName = e.FirstName,
+            MiddleName = e.MiddleName,
+            DepartmentTitle = e.DepartmentTitle,
+            DepartmentType = e.DepartmentType,
+            LocationSiteId = e.LocationSiteId,
+            GradeType = e.GradeType
+        };
+    }
+
+    public HrmsEmployeeInfo ToModel() => new()
+    {
+        ParentDocumentId = ParentDocumentId ?? string.Empty,
+        EmployeeId = EmployeeId ?? string.Empty,
+        UindSerial = UindSerial ?? string.Empty,
+        FunctionId = FunctionId,
+        DepartmentId = DepartmentId,
+        TagCreatedAtUtc = TagCreatedAtUtc,
+        TagCreatedBy = TagCreatedBy ?? string.Empty,
+        FirstName = FirstName ?? string.Empty,
+        MiddleName = MiddleName ?? string.Empty,
+        DepartmentTitle = DepartmentTitle ?? string.Empty,
+        DepartmentType = DepartmentType ?? string.Empty,
+        LocationSiteId = LocationSiteId ?? string.Empty,
+        GradeType = GradeType ?? string.Empty
+    };
+}
+
+public sealed class RfidScanResponseDto
+{
+    public bool Success { get; set; }
+    public string Message { get; set; } = string.Empty;
+    public int CooldownSecondsRemaining { get; set; }
+    public HrmsEmployeeInfoDto? Employee { get; set; }
+    public int MealSession { get; set; }
+    public string? EmployeeSiteId { get; set; }
+    public string? CurrentSiteId { get; set; }
+    public string? MealLabel { get; set; }
+    public string? MealItems { get; set; }
+    public double TotalPrice { get; set; }
+
+    public static RfidScanResponseDto FromScanResult(ScanResult r, string? mealLabel = null, string? mealItems = null, double totalPrice = 0)
+    {
+        return new RfidScanResponseDto
+        {
+            Success = r.Success,
+            Message = r.Message,
+            CooldownSecondsRemaining = r.CooldownSecondsRemaining,
+            Employee = HrmsEmployeeInfoDto.FromModel(r.EmployeeInfo),
+            MealSession = (int)r.MealSession,
+            EmployeeSiteId = r.EmployeeSiteId,
+            CurrentSiteId = r.CurrentSiteId,
+            MealLabel = mealLabel,
+            MealItems = mealItems,
+            TotalPrice = totalPrice
+        };
+    }
+}
+
+public sealed class ScanRecordDto
+{
+    public int Id { get; set; }
+    public string CardId { get; set; } = string.Empty;
+    public DateTime ScanTime { get; set; }
+    public bool IsSynced { get; set; }
+    public string SiteId { get; set; } = string.Empty;
+    public string DeviceId { get; set; } = string.Empty;
+    public string IpAddress { get; set; } = string.Empty;
+    public int MealSessionCode { get; set; }
+    public string ParentDocumentId { get; set; } = string.Empty;
+    public string EmployeeId { get; set; } = string.Empty;
+    public string UindSerial { get; set; } = string.Empty;
+    public int FunctionId { get; set; }
+    public int DepartmentId { get; set; }
+    public DateTime? TagCreatedAtUtc { get; set; }
+    public string TagCreatedBy { get; set; } = string.Empty;
+    public string EmployeeName { get; set; } = string.Empty;
+    public string Department { get; set; } = string.Empty;
+    public string DepartmentType { get; set; } = string.Empty;
+    public string MealLabel { get; set; } = string.Empty;
+    public string MealItems { get; set; } = string.Empty;
+    public double TotalPrice { get; set; }
+    [JsonPropertyName("grade_type")]
+    public string GradeType { get; set; } = string.Empty;
+
+    public static ScanRecordDto FromEntity(ScanRecord r) => new()
+    {
+        Id = r.Id,
+        CardId = r.CardId,
+        ScanTime = r.ScanTime,
+        IsSynced = r.IsSynced,
+        SiteId = r.SiteId,
+        DeviceId = r.DeviceId,
+        IpAddress = r.IpAddress,
+        MealSessionCode = r.MealSessionCode,
+        ParentDocumentId = r.ParentDocumentId,
+        EmployeeId = r.EmployeeId,
+        UindSerial = r.UindSerial,
+        FunctionId = r.FunctionId,
+        DepartmentId = r.DepartmentId,
+        TagCreatedAtUtc = r.TagCreatedAtUtc,
+        TagCreatedBy = r.TagCreatedBy,
+        EmployeeName = r.EmployeeName,
+        Department = r.Department,
+        DepartmentType = r.DepartmentType,
+        MealLabel = r.MealLabel,
+        MealItems = r.MealItems,
+        TotalPrice = r.TotalPrice,
+        GradeType = r.grade_type
+    };
+
+    public ScanRecord ToEntity() => new()
+    {
+        Id = Id,
+        CardId = CardId ?? string.Empty,
+        ScanTime = ScanTime,
+        IsSynced = IsSynced,
+        SiteId = SiteId ?? string.Empty,
+        DeviceId = DeviceId ?? string.Empty,
+        IpAddress = IpAddress ?? string.Empty,
+        MealSessionCode = MealSessionCode,
+        ParentDocumentId = ParentDocumentId ?? string.Empty,
+        EmployeeId = EmployeeId ?? string.Empty,
+        UindSerial = UindSerial ?? string.Empty,
+        FunctionId = FunctionId,
+        DepartmentId = DepartmentId,
+        TagCreatedAtUtc = TagCreatedAtUtc,
+        TagCreatedBy = TagCreatedBy ?? string.Empty,
+        EmployeeName = EmployeeName ?? string.Empty,
+        Department = Department ?? string.Empty,
+        DepartmentType = DepartmentType ?? string.Empty,
+        MealLabel = MealLabel ?? string.Empty,
+        MealItems = MealItems ?? string.Empty,
+        TotalPrice = TotalPrice,
+        grade_type = GradeType ?? string.Empty
+    };
+}

App.xaml.cs

@@ -1,21 +1,27 @@
-using Microsoft.EntityFrameworkCore;
 using System.Net.Http;
 using System.Threading;
 using System.Windows;
+using Microsoft.EntityFrameworkCore;
+using UtopiaCanteenSystem.Api;
 using UtopiaCanteenSystem.Data;
+using UtopiaCanteenSystem.Models;
 using UtopiaCanteenSystem.Services;
 using UtopiaCanteenSystem.ViewModels;
 
 namespace UtopiaCanteenSystem;
 
 /// <summary>
-/// Application entry point. Initializes database, builds service graph, starts hourly sync timer.
+/// WPF shell: Server = backend + SQLite + API host; Client = scanner frontend calling backend HTTP API only.
 /// </summary>
 public partial class App : Application
 {
-    private static Mutex _mutex;
+    private static Mutex _mutex = null!;
     private System.Timers.Timer? _syncTimer;
+    private System.Timers.Timer? _offlineCacheSyncTimer;
     private int _isSyncRunning;
+    private int _isOfflineCacheSyncRunning;
+    private CancellationTokenSource? _apiHostCts;
+    private Task? _apiHostTask;
 
     protected override void OnStartup(StartupEventArgs e)
     {
@@ -28,73 +34,134 @@ public partial class App : Application
             Current.Shutdown();
             return;
         }
+
         base.OnStartup(e);
 
-        // Build services (simple composition; no DI container)
+        var configService = new ConfigService();
-        var dbFactory = new DbContextFactory();
+        var isServer = configService.GetAppMode() == AppMode.Server;
+
+        var httpClient = new HttpClient { Timeout = TimeSpan.FromMinutes(5) };
+        var backendApiClient = new CanteenBackendApiClient(httpClient, configService);
+
+        var dbFactory = new DbContextFactory();
+        CanteenBackendServices? backendServices = null;
+        RfidService? serverRfid = null;
+        IEmployeeLookupService employeeLookupService;
+        IMenuLookupService menuLookupService;
+        IRfidService scannerRfidService;
+        ISyncService? syncService = null;
+        ProductionMealScheduleService? mealScheduleService = null;
 
-        // Auto-create SQLite database on first run
         using (var db = dbFactory.CreateDbContext())
-        {
             db.EnsureDatabaseCreated();
+
+        if (isServer)
+        {
+
+            var employeeRfidTagSync = new EmployeeRfidTagSyncService(dbFactory, configService);
+            var mealMenuCacheSync = new MealMenuCacheSyncService(dbFactory, configService);
+            var offlineCacheSync = new OfflineCacheSyncService(employeeRfidTagSync, mealMenuCacheSync);
+            employeeLookupService = new EmployeeLookupService(dbFactory, configService);
+            menuLookupService = new MenuLookupService(dbFactory);
+            mealScheduleService = new ProductionMealScheduleService(configService);
+            var mealSessionResolver = new DbMealSessionResolver(dbFactory);
+            syncService = new SyncService(dbFactory, configService);
+            serverRfid = new RfidService(dbFactory, configService, employeeLookupService, mealSessionResolver, menuLookupService, syncService);
+            backendServices = new CanteenBackendServices(serverRfid, offlineCacheSync, syncService, configService);
+            scannerRfidService = serverRfid;
+        }
+        else
+        {
+            employeeLookupService = new EmployeeLookupService(dbFactory, configService);
+            menuLookupService = new EmptyMenuLookupService();
+            scannerRfidService = backendApiClient;
         }
 
-        var configService = new ConfigService();
-        var employeeLookupService = new EmployeeLookupService(configService);
-        //var employeePhotoService = new EmployeePhotoService(configService);
-        var httpClient = new HttpClient();
         var employeePhotoService = new EmployeePhotoService(configService, httpClient);
-        var menuLookupService = new MenuLookupService(configService);
-        var mealScheduleService = new ProductionMealScheduleService(configService);
-        var mealSessionResolver = new DbMealSessionResolver(mealScheduleService);
-        var syncService = new SyncService(dbFactory, configService);
-        var rfidService = new RfidService(dbFactory, configService, employeeLookupService, mealSessionResolver, menuLookupService, syncService);
         var adminAuditService = new AdminAuditService(dbFactory);
         var session = new AppSession();
-        var authenticationUrl = "https://portal.utopiaindustries.pk/uind/rest/auth/user/";
+        var authService = new AuthService("https://portal.utopiaindustries.pk/uind/rest/auth/user/");
-        var authService = new AuthService(authenticationUrl);
 
-        // NavigationService: declare first so lambdas can capture it, then assign (avoids "used before declared")
         NavigationService navigationService = null!;
         navigationService = new NavigationService(
             session,
-            () => new AdminLoginViewModel(authService, session, navigationService, configService, adminAuditService, employeeLookupService),
+            () => new AdminLoginViewModel(authService, session, navigationService, configService, adminAuditService, employeeLookupService, backendApiClient),
-            () => new ScannerDashboardViewModel(rfidService, navigationService, session, configService, menuLookupService, employeePhotoService),
+            () => new ScannerDashboardViewModel(scannerRfidService, navigationService, session, configService, menuLookupService, employeePhotoService),
-            () => new MainDashboardViewModel(navigationService, rfidService, configService, session),
+            () => new MainDashboardViewModel(navigationService, scannerRfidService, configService, session),
-            () => new AdminSettingsAuthViewModel(authService, session, navigationService, configService, employeeLookupService),
+            () => new AdminSettingsAuthViewModel(authService, session, navigationService, configService, employeeLookupService, backendApiClient),
-            () => new SettingsViewModel(configService, navigationService, adminAuditService, syncService),
+            () => new SettingsViewModel(configService, navigationService, adminAuditService, backendApiClient),
-            () => new MealSchedulesViewModel(mealScheduleService, navigationService, configService));
+            () => new MealSchedulesViewModel(
+                mealScheduleService ?? new ProductionMealScheduleService(configService),
+                navigationService,
+                configService));
 
-        var mainViewModel = new MainViewModel(navigationService);
+        var mainWindow = new MainWindow { DataContext = new MainViewModel(navigationService) };
-
-        var mainWindow = new MainWindow
-        {
-            DataContext = mainViewModel
-        };
-        // Set the window to open maximized
         mainWindow.WindowState = WindowState.Maximized;
         mainWindow.Show();
 
-        // Background sync: every 15 minutes, POST unsynced lunch_order_transactions to API
+        if (isServer && backendServices != null)
-        if (configService.GetSyncServiceEnabled())
         {
-            _syncTimer = new System.Timers.Timer(TimeSpan.FromMinutes(1).TotalMilliseconds)
+            _apiHostCts = new CancellationTokenSource();
+            var listenUrls = configService.GetLocalServerListenUrls();
+            var backend = backendServices;
+            var cts = _apiHostCts;
+            _apiHostTask = Task.Run(async () =>
             {
-                AutoReset = true
-            };
-            _syncTimer.Elapsed += async (_, _) =>
-            {
-                // Prevent overlapping sync runs; if one is still running, skip this tick.
-                if (Interlocked.Exchange(ref _isSyncRunning, 1) == 1)
-                    return;
-
                 try
                 {
-                    await syncService.SyncNowAsync().ConfigureAwait(false);
+                    await Task.Delay(500, cts!.Token).ConfigureAwait(false);
+                    await CanteenBackendHost.RunAsync(backend, listenUrls, cts.Token).ConfigureAwait(false);
                 }
-                catch
+                catch (OperationCanceledException)
                 {
-                    // Ignore; will retry next tick
+                    // Shutdown
+                }
+                catch (Exception ex)
+                {
+                    Logger.Log(ex, "App.CanteenBackendHost");
+                }
+            }, CancellationToken.None);
+
+            _ = RunOfflineCacheSyncViaApiAsync(backendApiClient);
+
+            if (!string.IsNullOrWhiteSpace(configService.GetHrmsLookupConnectionString()))
+            {
+                _offlineCacheSyncTimer = new System.Timers.Timer(TimeSpan.FromMinutes(15).TotalMilliseconds) { AutoReset = true };
+                _offlineCacheSyncTimer.Elapsed += async (_, _) =>
+                {
+                    if (Interlocked.Exchange(ref _isOfflineCacheSyncRunning, 1) == 1)
+                        return;
+                    try
+                    {
+                        await RunOfflineCacheSyncViaApiAsync(backendApiClient).ConfigureAwait(false);
+                    }
+                    catch (Exception ex)
+                    {
+                        Logger.Log(ex, "App.OfflineCacheSyncTimer");
+                    }
+                    finally
+                    {
+                        Interlocked.Exchange(ref _isOfflineCacheSyncRunning, 0);
+                    }
+                };
+                _offlineCacheSyncTimer.Start();
+            }
+
+            if (configService.GetSyncServiceEnabled() && syncService != null)
+            {
+                _syncTimer = new System.Timers.Timer(TimeSpan.FromMinutes(1).TotalMilliseconds) { AutoReset = true };
+                _syncTimer.Elapsed += async (_, _) =>
+                {
+                    if (Interlocked.Exchange(ref _isSyncRunning, 1) == 1)
+                        return;
+                    try
+                    {
+                        if (await backendApiClient.HealthCheckAsync().ConfigureAwait(false))
+                            await backendApiClient.SyncOrdersNowAsync().ConfigureAwait(false);
+                    }
+                    catch (Exception ex)
+                    {
+                        Logger.Log(ex, "App.ProductionSyncTimer");
                     }
                     finally
                     {
@@ -104,12 +171,46 @@ public partial class App : Application
                 _syncTimer.Start();
             }
         }
+    }
 
     protected override void OnExit(ExitEventArgs e)
     {
+        try
+        {
+            _apiHostCts?.Cancel();
+            _apiHostTask?.Wait(TimeSpan.FromSeconds(5));
+        }
+        catch
+        {
+            // Best-effort
+        }
+
         _mutex.ReleaseMutex();
         _syncTimer?.Stop();
         _syncTimer?.Dispose();
+        _offlineCacheSyncTimer?.Stop();
+        _offlineCacheSyncTimer?.Dispose();
+        _apiHostCts?.Dispose();
         base.OnExit(e);
     }
+
+    private static async Task RunOfflineCacheSyncViaApiAsync(ICanteenBackendApiClient api)
+    {
+        try
+        {
+            for (var i = 0; i < 30; i++)
+            {
+                if (await api.HealthCheckAsync().ConfigureAwait(false))
+                {
+                    await api.SyncCacheNowAsync().ConfigureAwait(false);
+                    return;
+                }
+                await Task.Delay(1000).ConfigureAwait(false);
+            }
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "App.RunOfflineCacheSyncViaApiAsync");
+        }
+    }
 }

Data/AppDbContext.cs

@@ -18,6 +18,11 @@ public class AppDbContext : DbContext
     public DbSet<Labour> Labour { get; set; }
     public DbSet<ScanRecord> LunchOrderTransactions { get; set; }
     public DbSet<AdminLoginRecord> AdminLoginRecords { get; set; }
+    public DbSet<EmployeeRfidTagCache> EmployeeRfidTagCache { get; set; }
+    public DbSet<MealScheduleCache> MealScheduleCache { get; set; }
+    public DbSet<LunchMenuWeekCache> LunchMenuWeekCache { get; set; }
+    public DbSet<LunchMenuItemCache> LunchMenuItemCache { get; set; }
+    public DbSet<MenuItemCache> MenuItemCache { get; set; }
 
     public AppDbContext() { }
 
@@ -52,6 +57,46 @@ public class AppDbContext : DbContext
             e.HasKey(x => x.Id);
             e.HasIndex(x => x.LoginTimeUtc);
         });
+
+        modelBuilder.Entity<EmployeeRfidTagCache>(e =>
+        {
+            e.ToTable("employee_rfid_tag_cache");
+            e.HasKey(x => x.LocalId);
+            e.HasIndex(x => x.HrmsId).IsUnique();
+            e.HasIndex(x => x.ManufacturerSerial);
+        });
+
+        modelBuilder.Entity<MealScheduleCache>(e =>
+        {
+            e.ToTable("meal_schedule_cache");
+            e.HasKey(x => x.LocalId);
+            e.HasIndex(x => x.HrmsId).IsUnique();
+            e.HasIndex(x => x.LocationSiteId);
+        });
+
+        modelBuilder.Entity<LunchMenuWeekCache>(e =>
+        {
+            e.ToTable("lunch_menu_week_cache");
+            e.HasKey(x => x.LocalId);
+            e.HasIndex(x => x.HrmsId).IsUnique();
+            e.HasIndex(x => x.LocationSiteId);
+        });
+
+        modelBuilder.Entity<LunchMenuItemCache>(e =>
+        {
+            e.ToTable("lunch_menu_item_cache");
+            e.HasKey(x => x.LocalId);
+            e.HasIndex(x => x.HrmsId).IsUnique();
+            e.HasIndex(x => x.LunchMenuWeekHrmsId);
+            e.HasIndex(x => x.MenuDate);
+        });
+
+        modelBuilder.Entity<MenuItemCache>(e =>
+        {
+            e.ToTable("menu_item_cache");
+            e.HasKey(x => x.LocalId);
+            e.HasIndex(x => x.HrmsId).IsUnique();
+        });
     }
 
     /// <summary>
@@ -63,6 +108,8 @@ public class AppDbContext : DbContext
         MigrateScanRecordsToLunchOrderTransactionsIfNeeded();
         UpgradeLunchOrderTransactionsSchemaIfNeeded();
         EnsureAdminLoginTableExists();
+        EnsureEmployeeRfidTagCacheTableExists();
+        EnsureMealMenuCacheTablesExist();
         RemoveLegacyMealRelatedSchemaIfNeeded();
     }
 
@@ -401,6 +448,152 @@ public class AppDbContext : DbContext
         }
     }
 
+    /// <summary>
+    /// Lightweight creation of employee_rfid_tag_cache for existing databases (no EF migrations).
+    /// </summary>
+    private void EnsureEmployeeRfidTagCacheTableExists()
+    {
+        try
+        {
+            var conn = Database.GetDbConnection();
+            if (conn.State != ConnectionState.Open)
+                conn.Open();
+
+            using var cmd = conn.CreateCommand();
+            cmd.CommandText =
+                "CREATE TABLE IF NOT EXISTS employee_rfid_tag_cache (" +
+                "LocalId INTEGER PRIMARY KEY AUTOINCREMENT, " +
+                "HrmsId INTEGER NOT NULL, " +
+                "ManufacturerSerial TEXT NOT NULL DEFAULT '', " +
+                "UindSerial TEXT NOT NULL DEFAULT '', " +
+                "Secret TEXT NOT NULL DEFAULT '', " +
+                "ParentDocumentType TEXT NOT NULL DEFAULT '', " +
+                "ParentDocumentId TEXT NOT NULL DEFAULT '', " +
+                "DateTimeCreated TEXT, " +
+                "CreatedBy TEXT NOT NULL DEFAULT '', " +
+                "GradeId INTEGER, " +
+                "GradeType TEXT NOT NULL DEFAULT '', " +
+                "ShiftId INTEGER, " +
+                "LocationSiteId TEXT NOT NULL DEFAULT '', " +
+                "RfidLocationSiteId TEXT NOT NULL DEFAULT '', " +
+                "FunctionId INTEGER NOT NULL DEFAULT 0, " +
+                "DepartmentId INTEGER NOT NULL DEFAULT 0, " +
+                "ReportingManagerIds TEXT NOT NULL DEFAULT '', " +
+                "EmployeeSerialNumber TEXT NOT NULL DEFAULT '', " +
+                "EmployeeConcatenatedName TEXT NOT NULL DEFAULT '', " +
+                "DepartmentTitle TEXT NOT NULL DEFAULT '', " +
+                "DepartmentType TEXT NOT NULL DEFAULT '', " +
+                "LastSyncedAtUtc TEXT NOT NULL)";
+            cmd.ExecuteNonQuery();
+
+            using var idxHrms = conn.CreateCommand();
+            idxHrms.CommandText =
+                "CREATE UNIQUE INDEX IF NOT EXISTS IX_employee_rfid_tag_cache_HrmsId ON employee_rfid_tag_cache(HrmsId)";
+            idxHrms.ExecuteNonQuery();
+
+            using var idxSerial = conn.CreateCommand();
+            idxSerial.CommandText =
+                "CREATE INDEX IF NOT EXISTS IX_employee_rfid_tag_cache_ManufacturerSerial ON employee_rfid_tag_cache(ManufacturerSerial)";
+            idxSerial.ExecuteNonQuery();
+        }
+        catch
+        {
+            // Ignore; table may already exist or DB may be read-only.
+        }
+    }
+
+    private void EnsureMealMenuCacheTablesExist()
+    {
+        try
+        {
+            var conn = Database.GetDbConnection();
+            if (conn.State != ConnectionState.Open)
+                conn.Open();
+
+            using (var cmd = conn.CreateCommand())
+            {
+                cmd.CommandText =
+                    "CREATE TABLE IF NOT EXISTS meal_schedule_cache (" +
+                    "LocalId INTEGER PRIMARY KEY AUTOINCREMENT, " +
+                    "HrmsId INTEGER NOT NULL, " +
+                    "MealName TEXT NOT NULL DEFAULT '', " +
+                    "StartTime TEXT NOT NULL DEFAULT '', " +
+                    "EndTime TEXT NOT NULL DEFAULT '', " +
+                    "CreatedAt TEXT, " +
+                    "UpdatedAt TEXT, " +
+                    "LocationSiteId INTEGER NOT NULL DEFAULT 0, " +
+                    "LastSyncedAtUtc TEXT NOT NULL)";
+                cmd.ExecuteNonQuery();
+            }
+
+            using (var cmd = conn.CreateCommand())
+            {
+                cmd.CommandText =
+                    "CREATE TABLE IF NOT EXISTS lunch_menu_week_cache (" +
+                    "LocalId INTEGER PRIMARY KEY AUTOINCREMENT, " +
+                    "HrmsId INTEGER NOT NULL, " +
+                    "WeekStartDate TEXT, " +
+                    "WeekEndDate TEXT, " +
+                    "CreatedBy TEXT NOT NULL DEFAULT '', " +
+                    "CreatedAt TEXT, " +
+                    "LocationSiteId INTEGER NOT NULL DEFAULT 0, " +
+                    "LastSyncedAtUtc TEXT NOT NULL)";
+                cmd.ExecuteNonQuery();
+            }
+
+            using (var cmd = conn.CreateCommand())
+            {
+                cmd.CommandText =
+                    "CREATE TABLE IF NOT EXISTS lunch_menu_item_cache (" +
+                    "LocalId INTEGER PRIMARY KEY AUTOINCREMENT, " +
+                    "HrmsId INTEGER NOT NULL, " +
+                    "LunchMenuWeekHrmsId INTEGER NOT NULL DEFAULT 0, " +
+                    "DayOfWeek TEXT NOT NULL DEFAULT '', " +
+                    "MealName TEXT NOT NULL DEFAULT '', " +
+                    "MenuItemHrmsId INTEGER NOT NULL DEFAULT 0, " +
+                    "CreatedAt TEXT, " +
+                    "MenuDate TEXT, " +
+                    "LastSyncedAtUtc TEXT NOT NULL)";
+                cmd.ExecuteNonQuery();
+            }
+
+            using (var cmd = conn.CreateCommand())
+            {
+                cmd.CommandText =
+                    "CREATE TABLE IF NOT EXISTS menu_item_cache (" +
+                    "LocalId INTEGER PRIMARY KEY AUTOINCREMENT, " +
+                    "HrmsId INTEGER NOT NULL, " +
+                    "ItemName TEXT NOT NULL DEFAULT '', " +
+                    "ItemType TEXT NOT NULL DEFAULT '', " +
+                    "Price REAL NOT NULL DEFAULT 0, " +
+                    "ItemFor TEXT NOT NULL DEFAULT '', " +
+                    "LocationSiteId INTEGER NOT NULL DEFAULT 0, " +
+                    "LastSyncedAtUtc TEXT NOT NULL)";
+                cmd.ExecuteNonQuery();
+            }
+
+            CreateIndexIfNotExists(conn, "IX_meal_schedule_cache_HrmsId", "meal_schedule_cache", "HrmsId", unique: true);
+            CreateIndexIfNotExists(conn, "IX_meal_schedule_cache_LocationSiteId", "meal_schedule_cache", "LocationSiteId", unique: false);
+            CreateIndexIfNotExists(conn, "IX_lunch_menu_week_cache_HrmsId", "lunch_menu_week_cache", "HrmsId", unique: true);
+            CreateIndexIfNotExists(conn, "IX_lunch_menu_week_cache_LocationSiteId", "lunch_menu_week_cache", "LocationSiteId", unique: false);
+            CreateIndexIfNotExists(conn, "IX_lunch_menu_item_cache_HrmsId", "lunch_menu_item_cache", "HrmsId", unique: true);
+            CreateIndexIfNotExists(conn, "IX_lunch_menu_item_cache_WeekId", "lunch_menu_item_cache", "LunchMenuWeekHrmsId", unique: false);
+            CreateIndexIfNotExists(conn, "IX_menu_item_cache_HrmsId", "menu_item_cache", "HrmsId", unique: true);
+        }
+        catch
+        {
+            // Ignore; table may already exist or DB may be read-only.
+        }
+    }
+
+    private static void CreateIndexIfNotExists(DbConnection conn, string indexName, string tableName, string columnName, bool unique)
+    {
+        using var cmd = conn.CreateCommand();
+        var uniqueSql = unique ? "UNIQUE " : string.Empty;
+        cmd.CommandText = $"CREATE {uniqueSql}INDEX IF NOT EXISTS {indexName} ON {tableName}({columnName})";
+        cmd.ExecuteNonQuery();
+    }
+
     /// <summary>
     /// Removes legacy meal-related tables and columns that should never be present in production.
     /// This is a best-effort cleanup that runs on every startup for existing SQLite databases.

Data/DatabasePath.cs

@@ -1,4 +1,5 @@
 using System.IO;
+using UtopiaCanteenSystem.Services.Logging;
 
 namespace UtopiaCanteenSystem.Data;
 
@@ -10,6 +11,27 @@ public static class DatabasePath
 {
     private static string? _appDataFolder;
     private static string? _dbPath;
+    private static string _productFolderName = "UtopiaCanteenSystem";
+    private static bool _useInteractiveLocalAppData;
+
+    /// <summary>
+    /// Use "UtopiaCanteenBackend" for the Windows Service; default is legacy WPF folder name.
+    /// </summary>
+    public static void UseBackendServiceStorage()
+    {
+        _productFolderName = "UtopiaCanteenBackend";
+        _useInteractiveLocalAppData = true;
+        _appDataFolder = null;
+        _dbPath = null;
+    }
+
+    public static void UseClientStorage()
+    {
+        _productFolderName = "UtopiaCanteenClient";
+        _useInteractiveLocalAppData = false;
+        _appDataFolder = null;
+        _dbPath = null;
+    }
 
     /// <summary>
     /// Folder under LocalApplicationData for DB and config. Created on first use.
@@ -19,13 +41,65 @@ public static class DatabasePath
         if (_appDataFolder != null)
             return _appDataFolder;
 
-        _appDataFolder = Path.Combine(
+        var localAppDataRoot = ResolveLocalAppDataRoot();
-            Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
+        _appDataFolder = Path.Combine(localAppDataRoot, _productFolderName);
-            "UtopiaCanteenSystem");
         Directory.CreateDirectory(_appDataFolder);
+        MigrateBackendSystemProfileStorageIfNeeded(_appDataFolder);
         return _appDataFolder;
     }
 
+    private static string ResolveLocalAppDataRoot()
+    {
+        if (_useInteractiveLocalAppData)
+        {
+            var interactive = InteractiveUserPath.TryGetLocalAppDataPath();
+            if (!string.IsNullOrWhiteSpace(interactive))
+                return interactive;
+        }
+
+        return Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+    }
+
+    private static void MigrateBackendSystemProfileStorageIfNeeded(string newFolder)
+    {
+        if (!_useInteractiveLocalAppData)
+            return;
+
+        var systemProfileFolder = Path.Combine(
+            Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
+            _productFolderName);
+
+        if (string.Equals(systemProfileFolder, newFolder, StringComparison.OrdinalIgnoreCase) ||
+            !Directory.Exists(systemProfileFolder))
+            return;
+
+        var oldDbPath = Path.Combine(systemProfileFolder, "utopia_canteen.db");
+        var newDbPath = Path.Combine(newFolder, "utopia_canteen.db");
+        if (File.Exists(oldDbPath) && !File.Exists(newDbPath))
+        {
+            CopyIfMissing(oldDbPath, newDbPath);
+            CopyIfMissing(Path.Combine(systemProfileFolder, "utopia_canteen.db-wal"), Path.Combine(newFolder, "utopia_canteen.db-wal"));
+            CopyIfMissing(Path.Combine(systemProfileFolder, "utopia_canteen.db-shm"), Path.Combine(newFolder, "utopia_canteen.db-shm"));
+        }
+
+        CopyIfMissing(Path.Combine(systemProfileFolder, "backend-settings.json"), Path.Combine(newFolder, "backend-settings.json"));
+    }
+
+    private static void CopyIfMissing(string sourcePath, string destinationPath)
+    {
+        if (!File.Exists(sourcePath) || File.Exists(destinationPath))
+            return;
+
+        try
+        {
+            File.Copy(sourcePath, destinationPath);
+        }
+        catch
+        {
+            // If migration fails, the app will continue with files already present or create new ones.
+        }
+    }
+
     /// <summary>
     /// Full path to the SQLite database file. If a DB exists in the legacy app-directory
     /// location, it is copied to the new location once.

Models/AppMode.cs

@@ -0,0 +1,10 @@
+namespace UtopiaCanteenSystem.Models;
+
+/// <summary>
+/// Deployment role: central PC hosts SQLite and HTTP API; scanner PCs call the API only.
+/// </summary>
+public enum AppMode
+{
+    Server = 0,
+    Client = 1
+}

Models/EmployeeRfidTagCache.cs

@@ -0,0 +1,43 @@
+namespace UtopiaCanteenSystem.Models;
+
+/// <summary>
+/// Local SQLite cache of production <c>hrms.employee_rfid_tag</c>, plus denormalized employee/department
+/// fields populated during sync for offline RFID lookup.
+/// </summary>
+public class EmployeeRfidTagCache
+{
+    public int LocalId { get; set; }
+
+    /// <summary>Production <c>employee_rfid_tag.id</c>.</summary>
+    public long HrmsId { get; set; }
+
+    public string ManufacturerSerial { get; set; } = string.Empty;
+    public string UindSerial { get; set; } = string.Empty;
+    public string Secret { get; set; } = string.Empty;
+    public string ParentDocumentType { get; set; } = string.Empty;
+    public string ParentDocumentId { get; set; } = string.Empty;
+    public DateTime? DateTimeCreated { get; set; }
+    public string CreatedBy { get; set; } = string.Empty;
+    public int? GradeId { get; set; }
+    public string GradeType { get; set; } = string.Empty;
+    public int? ShiftId { get; set; }
+    public string LocationSiteId { get; set; } = string.Empty;
+    public string RfidLocationSiteId { get; set; } = string.Empty;
+    public int FunctionId { get; set; }
+    public int DepartmentId { get; set; }
+    public string ReportingManagerIds { get; set; } = string.Empty;
+
+    /// <summary><c>employee.serial_number</c> from sync join.</summary>
+    public string EmployeeSerialNumber { get; set; } = string.Empty;
+
+    /// <summary><c>employee.concatenated_name</c> from sync join.</summary>
+    public string EmployeeConcatenatedName { get; set; } = string.Empty;
+
+    /// <summary><c>department.title</c> from sync join.</summary>
+    public string DepartmentTitle { get; set; } = string.Empty;
+
+    /// <summary><c>department.department_type</c> from sync join.</summary>
+    public string DepartmentType { get; set; } = string.Empty;
+
+    public DateTime LastSyncedAtUtc { get; set; }
+}

Models/HrmsEmployeeInfo.cs

@@ -1,7 +1,7 @@
 namespace UtopiaCanteenSystem.Models;
 
 /// <summary>
-/// Employee info loaded from local HRMS by RFID (employee_rfid_tag → employee → department).
+/// Employee info from offline RFID cache (synced from employee_rfid_tag → employee → department).
 /// </summary>
 public class HrmsEmployeeInfo
 {

Models/LunchMenuItemCache.cs

@@ -0,0 +1,15 @@
+namespace UtopiaCanteenSystem.Models;
+
+/// <summary>Local SQLite cache of production <c>hrms.lunch_menu_item</c>.</summary>
+public class LunchMenuItemCache
+{
+    public int LocalId { get; set; }
+    public long HrmsId { get; set; }
+    public long LunchMenuWeekHrmsId { get; set; }
+    public string DayOfWeek { get; set; } = string.Empty;
+    public string MealName { get; set; } = string.Empty;
+    public long MenuItemHrmsId { get; set; }
+    public DateTime? CreatedAt { get; set; }
+    public DateTime? MenuDate { get; set; }
+    public DateTime LastSyncedAtUtc { get; set; }
+}

Models/LunchMenuWeekCache.cs

@@ -0,0 +1,14 @@
+namespace UtopiaCanteenSystem.Models;
+
+/// <summary>Local SQLite cache of production <c>hrms.lunch_menu_week</c>.</summary>
+public class LunchMenuWeekCache
+{
+    public int LocalId { get; set; }
+    public long HrmsId { get; set; }
+    public DateTime? WeekStartDate { get; set; }
+    public DateTime? WeekEndDate { get; set; }
+    public string CreatedBy { get; set; } = string.Empty;
+    public DateTime? CreatedAt { get; set; }
+    public int LocationSiteId { get; set; }
+    public DateTime LastSyncedAtUtc { get; set; }
+}

Models/MealScheduleCache.cs

@@ -0,0 +1,15 @@
+namespace UtopiaCanteenSystem.Models;
+
+/// <summary>Local SQLite cache of production <c>hrms.meal_schedule</c>.</summary>
+public class MealScheduleCache
+{
+    public int LocalId { get; set; }
+    public long HrmsId { get; set; }
+    public string MealName { get; set; } = string.Empty;
+    public string StartTime { get; set; } = string.Empty;
+    public string EndTime { get; set; } = string.Empty;
+    public DateTime? CreatedAt { get; set; }
+    public DateTime? UpdatedAt { get; set; }
+    public int LocationSiteId { get; set; }
+    public DateTime LastSyncedAtUtc { get; set; }
+}

Models/MenuItemCache.cs

@@ -0,0 +1,14 @@
+namespace UtopiaCanteenSystem.Models;
+
+/// <summary>Local SQLite cache of production <c>hrms.menu_item</c>.</summary>
+public class MenuItemCache
+{
+    public int LocalId { get; set; }
+    public long HrmsId { get; set; }
+    public string ItemName { get; set; } = string.Empty;
+    public string ItemType { get; set; } = string.Empty;
+    public decimal Price { get; set; }
+    public string ItemFor { get; set; } = string.Empty;
+    public int LocationSiteId { get; set; }
+    public DateTime LastSyncedAtUtc { get; set; }
+}

Models/RfidScanClientContext.cs

@@ -0,0 +1,11 @@
+namespace UtopiaCanteenSystem.Models;
+
+/// <summary>
+/// Per-scan context from a scanner PC (API client). Used on the central server instead of server-local config for site/device/IP.
+/// </summary>
+public sealed class RfidScanClientContext
+{
+    public string DeviceId { get; init; } = string.Empty;
+    public string SiteId { get; init; } = string.Empty;
+    public string IpAddress { get; init; } = string.Empty;
+}

Services/AdminAuditService.cs

@@ -32,9 +32,10 @@ public class AdminAuditService : IAdminAuditService
             db.AdminLoginRecords.Add(record);
             await db.SaveChangesAsync().ConfigureAwait(false);
         }
-        catch
+        catch (Exception ex)
         {
-            // Audit failures should never block login; ignore errors.
+            // Audit failures should never block login.
+            Logger.Log(ex, "AdminAuditService.RecordLoginAsync");
         }
     }
 
@@ -50,8 +51,9 @@ public class AdminAuditService : IAdminAuditService
                 .OrderByDescending(x => x.LoginTimeUtc)
                 .FirstOrDefault();
         }
-        catch
+        catch (Exception ex)
         {
+            Logger.Log(ex, "AdminAuditService.GetLastLogin");
             return null;
         }
     }

Services/AdminLoginHelper.cs

@@ -0,0 +1,97 @@
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Shared admin login post-processing: persist employee id and site from session/backend.
+/// </summary>
+public static class AdminLoginHelper
+{
+    /// <summary>
+    /// Admin Access field: persisted <see cref="IConfigService.GetAdminCardId"/> first,
+    /// then current session, then SQLite audit, then "ADMIN".
+    /// </summary>
+    public static string ResolveAdminCardIdForDisplay(
+        IConfigService config,
+        AppSession? session = null,
+        IAdminAuditService? adminAudit = null)
+    {
+        var fromConfig = (config.GetAdminCardId() ?? string.Empty).Trim();
+        if (!string.IsNullOrWhiteSpace(fromConfig))
+            return fromConfig;
+
+        if (session != null && !string.IsNullOrWhiteSpace(session.AdminEmployeeId))
+            return session.AdminEmployeeId.Trim();
+
+        var last = adminAudit?.GetLastLogin();
+        if (last != null && !string.IsNullOrWhiteSpace(last.EmployeeId))
+            return last.EmployeeId.Trim();
+
+        return "ADMIN";
+    }
+
+    public static async Task ApplyAdminLoginDefaultsAsync(
+        string employeeId,
+        IConfigService config,
+        IEmployeeLookupService employeeLookup,
+        ICanteenBackendApiClient? backendApi = null,
+        CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrWhiteSpace(employeeId))
+            return;
+
+        config.SetAdminCardId(employeeId.Trim());
+
+        string? siteId = null;
+        try
+        {
+            siteId = await employeeLookup.GetLocationSiteIdByEmployeeSerialAsync(employeeId, cancellationToken)
+                .ConfigureAwait(false);
+        }
+        catch
+        {
+            // Local/HRMS lookup optional on client.
+        }
+
+        if (string.IsNullOrWhiteSpace(siteId) && backendApi != null)
+        {
+            try
+            {
+                siteId = await backendApi.GetEmployeeLocationSiteAsync(employeeId, cancellationToken)
+                    .ConfigureAwait(false);
+            }
+            catch
+            {
+                // Backend lookup optional.
+            }
+        }
+
+        config.ApplyLocationSiteIdFromAuth(siteId);
+    }
+
+    /// <summary>Format site for UI fields (e.g. "SITE : 02").</summary>
+    public static string FormatSiteIdForDisplay(string? siteId)
+    {
+        if (string.IsNullOrWhiteSpace(siteId))
+            return string.Empty;
+
+        var raw = siteId.Trim();
+        if (raw.StartsWith("SITE :", StringComparison.OrdinalIgnoreCase))
+            return raw;
+
+        var digits = new string(raw.Where(char.IsDigit).ToArray());
+        return string.IsNullOrEmpty(digits) ? raw : $"SITE : {digits}";
+    }
+
+    /// <summary>Extract digits from site display for scanner header.</summary>
+    public static string ExtractSiteDigits(string? siteId)
+    {
+        if (string.IsNullOrWhiteSpace(siteId))
+            return "1";
+
+        var raw = siteId.Trim();
+        if (raw.StartsWith("SITE :", StringComparison.OrdinalIgnoreCase))
+            raw = raw.Substring(raw.IndexOf(':') + 1).Trim();
+
+        var digits = new string(raw.Where(char.IsDigit).ToArray());
+        return string.IsNullOrEmpty(digits) ? "1" : digits;
+    }
+}

Services/BackendApiMealScheduleService.cs

@@ -0,0 +1,48 @@
+using UtopiaCanteen.Shared;
+using UtopiaCanteenSystem.Api;
+using UtopiaCanteenSystem.Models;
+
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Meal schedule CRUD via central backend API (client never touches HRMS/MySQL).
+/// </summary>
+public sealed class BackendApiMealScheduleService : IMealScheduleService
+{
+    private readonly ICanteenBackendApiClient _api;
+
+    public BackendApiMealScheduleService(ICanteenBackendApiClient api)
+    {
+        _api = api;
+    }
+
+    public IReadOnlyList<MealSchedule> GetActiveSchedulesForSite(string siteId)
+    {
+        var all = GetAllSchedulesAsync().GetAwaiter().GetResult();
+        if (string.IsNullOrWhiteSpace(siteId))
+            return all;
+        var site = siteId.Trim().Replace("SITE : ", "", StringComparison.OrdinalIgnoreCase).Trim();
+        return all.Where(s => string.Equals(s.LocationSiteId?.Trim(), site, StringComparison.OrdinalIgnoreCase)).ToList();
+    }
+
+    public async Task<IReadOnlyList<MealSchedule>> GetAllSchedulesAsync(CancellationToken cancellationToken = default)
+    {
+        var dtos = await _api.GetMealSchedulesAsync(cancellationToken).ConfigureAwait(false);
+        return dtos.Select(ApiDtoMapper.ToMealSchedule).ToList();
+    }
+
+    public async Task<long> CreateAsync(MealSchedule schedule, CancellationToken cancellationToken = default)
+    {
+        var dto = ApiDtoMapper.ToMealScheduleDto(schedule);
+        return await _api.CreateMealScheduleAsync(dto, cancellationToken).ConfigureAwait(false);
+    }
+
+    public async Task UpdateAsync(MealSchedule schedule, CancellationToken cancellationToken = default)
+    {
+        var dto = ApiDtoMapper.ToMealScheduleDto(schedule);
+        await _api.UpdateMealScheduleAsync(dto, cancellationToken).ConfigureAwait(false);
+    }
+
+    public async Task DeleteAsync(long id, CancellationToken cancellationToken = default) =>
+        await _api.DeleteMealScheduleAsync(id, cancellationToken).ConfigureAwait(false);
+}

Services/CanteenBackendApiClient.cs

@@ -0,0 +1,372 @@
+using System.Net.Http;
+using System.Net.Http.Json;
+using System.Text.Json;
+using UtopiaCanteen.Shared;
+using UtopiaCanteenSystem.Api;
+using UtopiaCanteenSystem.Models;
+using UtopiaCanteenSystem.Services.Logging;
+
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Frontend HTTP client: all scan/history/stats and settings actions go through the central backend API.
+/// </summary>
+public class CanteenBackendApiClient : ICanteenBackendApiClient
+{
+    private readonly HttpClient _http;
+    private readonly IConfigService _config;
+
+    private static readonly JsonSerializerOptions JsonOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        PropertyNameCaseInsensitive = true
+    };
+
+    public CanteenBackendApiClient(HttpClient http, IConfigService config)
+    {
+        _http = http;
+        _config = config;
+    }
+
+    private string BaseUrl => (_config.GetBackendBaseUrl() ?? string.Empty).TrimEnd('/');
+
+    public async Task<bool> HealthCheckAsync(CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrWhiteSpace(BaseUrl))
+        {
+            FileLogger.Warn("ClientApi", "Health check skipped. Backend base URL is not configured.");
+            return false;
+        }
+        try
+        {
+            var url = $"{BaseUrl}/api/health";
+            var resp = await _http.GetFromJsonAsync<HealthResponse>(url, JsonOptions, cancellationToken).ConfigureAwait(false);
+            var ok = resp != null && string.Equals(resp.Status, "ok", StringComparison.OrdinalIgnoreCase);
+            if (ok)
+                FileLogger.Info("ClientApi", $"Health check succeeded. Url={BaseUrl}");
+            else
+                FileLogger.Warn("ClientApi", $"Health check failed (unexpected response). Url={BaseUrl}");
+            return ok;
+        }
+        catch (Exception ex)
+        {
+            FileLogger.Error("ClientApi", $"Health check failed. Url={BaseUrl}", ex);
+            Logger.Log(ex, "CanteenBackendApiClient.HealthCheckAsync");
+            return false;
+        }
+    }
+
+    public async Task<ManualSyncResponse> SyncCacheNowAsync(CancellationToken cancellationToken = default) =>
+        await PostJobAsync("/api/cache/sync-now", cancellationToken).ConfigureAwait(false);
+
+    public async Task<ManualSyncResponse> SyncOrdersNowAsync(CancellationToken cancellationToken = default) =>
+        await PostJobAsync("/api/orders/sync-now", cancellationToken).ConfigureAwait(false);
+
+    public async Task<CacheStatusResponse?> GetCacheStatusAsync(CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrWhiteSpace(BaseUrl))
+            return null;
+        try
+        {
+            var url = $"{BaseUrl}/api/cache/status";
+            return await _http.GetFromJsonAsync<CacheStatusResponse>(url, JsonOptions, cancellationToken).ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "CanteenBackendApiClient.GetCacheStatusAsync");
+            return null;
+        }
+    }
+
+    public (bool Success, string Message) ProcessScan(string cardId)
+    {
+        var r = ProcessScanDetailed(cardId);
+        return (r.Success, r.Message);
+    }
+
+    public ScanResult ProcessScanDetailed(string cardId)
+    {
+        if (string.IsNullOrWhiteSpace(BaseUrl))
+            return new ScanResult(false, "Backend URL is not configured.", 0);
+
+        FileLogger.Info(
+            "ClientApi",
+            $"API scan request started. CardId={LogMasking.MaskCardId(cardId)}, POST {BaseUrl}/api/rfid/scan");
+
+        try
+        {
+            var url = $"{BaseUrl}/api/rfid/scan";
+            var body = new ScanRequest
+            {
+                CardId = cardId?.Trim() ?? string.Empty,
+                DeviceId = _config.GetDeviceId(),
+                SiteId = _config.GetSiteId(),
+                IpAddress = null
+            };
+
+            using var response = _http.PostAsJsonAsync(url, body, JsonOptions).GetAwaiter().GetResult();
+            if (!response.IsSuccessStatusCode)
+            {
+                var err = response.Content.ReadAsStringAsync().GetAwaiter().GetResult();
+                var fail = new ScanResult(false,
+                    $"Backend error ({(int)response.StatusCode}): {Truncate(err, 200)}", 0);
+                FileLogger.Warn("ClientApi", $"API scan request failed. Success=false, Message={fail.Message}");
+                return fail;
+            }
+
+            var dto = response.Content.ReadFromJsonAsync<ScanResponse>(JsonOptions).GetAwaiter().GetResult();
+            if (dto == null)
+            {
+                FileLogger.Warn("ClientApi", "API scan request failed. Invalid response from backend.");
+                return new ScanResult(false, "Invalid response from backend.", 0);
+            }
+
+            var scanResult = new ScanResult(
+                dto.Success,
+                dto.Message ?? string.Empty,
+                dto.CooldownSecondsRemaining,
+                dto.Employee == null ? null : ApiDtoMapper.ToModel(dto.Employee),
+                (MealSession)dto.MealSession,
+                dto.EmployeeSiteId,
+                dto.CurrentSiteId);
+
+            FileLogger.Info(
+                "ClientApi",
+                $"API scan request completed. Success={scanResult.Success}, Message={scanResult.Message}");
+            return scanResult;
+        }
+        catch (Exception ex)
+        {
+            FileLogger.Error("ClientApi", "API scan request failed with exception.", ex);
+            Logger.Log(ex, "CanteenBackendApiClient.ProcessScanDetailed");
+            return new ScanResult(false, "Cannot reach backend: " + ex.Message, 0);
+        }
+    }
+
+    public ScanRecord? GetLastScan() =>
+        GetAsync<RecentScanDto?, ScanRecord?>("/api/rfid/scans/last", d => d == null ? null : ApiDtoMapper.ToEntity(d));
+
+    public IReadOnlyList<ScanRecord> GetLastScans(int count)
+    {
+        if (count <= 0) return Array.Empty<ScanRecord>();
+        return GetAsync<List<RecentScanDto>, IReadOnlyList<ScanRecord>>(
+            $"/api/rfid/scans/recent?count={count}",
+            list => list?.Select(ApiDtoMapper.ToEntity).ToList() ?? new List<ScanRecord>());
+    }
+
+    public IReadOnlyList<ScanRecord> GetScansForToday() =>
+        GetAsync<List<RecentScanDto>, IReadOnlyList<ScanRecord>>(
+            "/api/rfid/scans/today",
+            list => list?.Select(ApiDtoMapper.ToEntity).ToList() ?? new List<ScanRecord>());
+
+    public int GetTodayScanCount() => GetTodayScanCountAsync().GetAwaiter().GetResult();
+
+    public async Task<int> GetTodayScanCountAsync(CancellationToken cancellationToken = default) =>
+        await GetCountAsync("/api/rfid/stats/today", cancellationToken).ConfigureAwait(false);
+
+    public async Task<int> GetTotalScanCountAsync(CancellationToken cancellationToken = default) =>
+        await GetCountAsync("/api/rfid/stats/total", cancellationToken).ConfigureAwait(false);
+
+    public async Task<int> GetTotalScanCountForCardAsync(string cardId, CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrWhiteSpace(cardId)) return 0;
+        return await GetCountAsync($"/api/rfid/stats/total-for-card?cardId={Uri.EscapeDataString(cardId.Trim())}", cancellationToken)
+            .ConfigureAwait(false);
+    }
+
+    public async Task<int> GetTodayScanCountForCardAsync(string cardId, CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrWhiteSpace(cardId)) return 0;
+        return await GetCountAsync($"/api/rfid/stats/today-for-card?cardId={Uri.EscapeDataString(cardId.Trim())}", cancellationToken)
+            .ConfigureAwait(false);
+    }
+
+    public void UpdateLastScanMealInfo(string mealLabel, string mealItems, double totalPrice)
+    {
+        // Backend owns SQLite; no local update on frontend.
+    }
+
+    private async Task<ManualSyncResponse> PostJobAsync(string path, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(BaseUrl))
+        {
+            return new ManualSyncResponse
+            {
+                Success = false,
+                Message = "Backend URL is not configured."
+            };
+        }
+
+        var url = $"{BaseUrl}{path}";
+        FileLogger.Info("ClientApi", $"POST {url} started.");
+
+        try
+        {
+            using var response = await _http.PostAsync(url, null, cancellationToken).ConfigureAwait(false);
+            var dto = await response.Content.ReadFromJsonAsync<ManualSyncResponse>(JsonOptions, cancellationToken)
+                .ConfigureAwait(false);
+            if (dto != null)
+            {
+                FileLogger.Info(
+                    "ClientApi",
+                    $"POST {path} completed. Success={dto.Success}, Message={dto.Message}, Details={dto.Details}");
+                return dto;
+            }
+
+            if (!response.IsSuccessStatusCode)
+            {
+                var err = await response.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);
+                var fail = new ManualSyncResponse
+                {
+                    Success = false,
+                    Message = $"Backend error ({(int)response.StatusCode}): {Truncate(err, 200)}"
+                };
+                FileLogger.Warn("ClientApi", $"POST {path} failed. {fail.Message}");
+                return fail;
+            }
+
+            FileLogger.Warn("ClientApi", $"POST {path} failed. Invalid response from backend.");
+            return new ManualSyncResponse { Success = false, Message = "Invalid response from backend." };
+        }
+        catch (Exception ex)
+        {
+            FileLogger.Error("ClientApi", $"POST {path} failed with exception.", ex);
+            Logger.Log(ex, $"CanteenBackendApiClient.PostJobAsync{path}");
+            return new ManualSyncResponse
+            {
+                Success = false,
+                Message = "Cannot reach backend: " + ex.Message
+            };
+        }
+    }
+
+    private async Task<int> GetCountAsync(string path, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(BaseUrl)) return 0;
+        try
+        {
+            var url = $"{BaseUrl}{path}";
+            var wrap = await _http.GetFromJsonAsync<StatsDto>(url, JsonOptions, cancellationToken).ConfigureAwait(false);
+            return wrap?.Count ?? 0;
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, $"CanteenBackendApiClient.GetCountAsync{path}");
+            return 0;
+        }
+    }
+
+    private TResult GetAsync<TResponse, TResult>(string path, Func<TResponse?, TResult> map)
+    {
+        if (string.IsNullOrWhiteSpace(BaseUrl))
+            return map(default);
+        try
+        {
+            var url = $"{BaseUrl}{path}";
+            var data = _http.GetFromJsonAsync<TResponse>(url, JsonOptions).GetAwaiter().GetResult();
+            return map(data);
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, $"CanteenBackendApiClient.GetAsync{path}");
+            return map(default);
+        }
+    }
+
+    public async Task<HealthResponse?> GetHealthAsync(CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrWhiteSpace(BaseUrl))
+            return null;
+        try
+        {
+            return await _http.GetFromJsonAsync<HealthResponse>($"{BaseUrl}/api/health", JsonOptions, cancellationToken)
+                .ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "CanteenBackendApiClient.GetHealthAsync");
+            return null;
+        }
+    }
+
+    public async Task<IReadOnlyList<MealScheduleDto>> GetMealSchedulesAsync(CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrWhiteSpace(BaseUrl))
+            return Array.Empty<MealScheduleDto>();
+        try
+        {
+            var list = await _http.GetFromJsonAsync<List<MealScheduleDto>>($"{BaseUrl}/api/meal-schedules", JsonOptions, cancellationToken)
+                .ConfigureAwait(false);
+            return list ?? new List<MealScheduleDto>();
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "CanteenBackendApiClient.GetMealSchedulesAsync");
+            return Array.Empty<MealScheduleDto>();
+        }
+    }
+
+    public async Task<long> CreateMealScheduleAsync(MealScheduleDto schedule, CancellationToken cancellationToken = default)
+    {
+        EnsureBaseUrl();
+        var url = $"{BaseUrl}/api/meal-schedules";
+        using var response = await _http.PostAsJsonAsync(url, schedule, JsonOptions, cancellationToken).ConfigureAwait(false);
+        await EnsureSuccessAsync(response, cancellationToken).ConfigureAwait(false);
+        var created = await response.Content.ReadFromJsonAsync<MealScheduleDto>(JsonOptions, cancellationToken).ConfigureAwait(false);
+        return created?.Id ?? 0;
+    }
+
+    public async Task UpdateMealScheduleAsync(MealScheduleDto schedule, CancellationToken cancellationToken = default)
+    {
+        EnsureBaseUrl();
+        var url = $"{BaseUrl}/api/meal-schedules/{schedule.Id}";
+        using var response = await _http.PutAsJsonAsync(url, schedule, JsonOptions, cancellationToken).ConfigureAwait(false);
+        await EnsureSuccessAsync(response, cancellationToken).ConfigureAwait(false);
+    }
+
+    public async Task DeleteMealScheduleAsync(long id, CancellationToken cancellationToken = default)
+    {
+        EnsureBaseUrl();
+        var url = $"{BaseUrl}/api/meal-schedules/{id}";
+        using var response = await _http.DeleteAsync(url, cancellationToken).ConfigureAwait(false);
+        await EnsureSuccessAsync(response, cancellationToken).ConfigureAwait(false);
+    }
+
+    public async Task<string?> GetEmployeeLocationSiteAsync(string employeeId, CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrWhiteSpace(BaseUrl) || string.IsNullOrWhiteSpace(employeeId))
+            return null;
+        try
+        {
+            var url = $"{BaseUrl}/api/employees/location-site?employeeId={Uri.EscapeDataString(employeeId.Trim())}";
+            var resp = await _http.GetFromJsonAsync<EmployeeLocationSiteResponse>(url, JsonOptions, cancellationToken)
+                .ConfigureAwait(false);
+            return string.IsNullOrWhiteSpace(resp?.LocationSiteId) ? null : resp.LocationSiteId.Trim();
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "CanteenBackendApiClient.GetEmployeeLocationSiteAsync");
+            return null;
+        }
+    }
+
+    private void EnsureBaseUrl()
+    {
+        if (string.IsNullOrWhiteSpace(BaseUrl))
+            throw new InvalidOperationException("Backend URL is not configured.");
+    }
+
+    private static async Task EnsureSuccessAsync(HttpResponseMessage response, CancellationToken cancellationToken)
+    {
+        if (response.IsSuccessStatusCode)
+            return;
+        var err = await response.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);
+        throw new HttpRequestException($"Backend error ({(int)response.StatusCode}): {Truncate(err, 300)}");
+    }
+
+    private static string Truncate(string s, int max)
+    {
+        if (string.IsNullOrEmpty(s) || s.Length <= max) return s;
+        return s.Substring(0, max) + "…";
+    }
+}

Services/CanteenBackendServices.cs

@@ -0,0 +1,54 @@
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Server-side backend dependencies: SQLite, RFID processing, HRMS cache sync, production post.
+/// Only constructed when <see cref="Models.AppMode.Server"/>.
+/// </summary>
+public sealed class CanteenBackendServices
+{
+    private readonly SemaphoreSlim _cacheSyncLock = new(1, 1);
+    private readonly SemaphoreSlim _orderSyncLock = new(1, 1);
+
+    public CanteenBackendServices(
+        RfidService rfid,
+        IOfflineCacheSyncService offlineCacheSync,
+        ISyncService productionSync,
+        IConfigService config)
+    {
+        Rfid = rfid;
+        OfflineCacheSync = offlineCacheSync;
+        ProductionSync = productionSync;
+        Config = config;
+    }
+
+    public RfidService Rfid { get; }
+    public IOfflineCacheSyncService OfflineCacheSync { get; }
+    public ISyncService ProductionSync { get; }
+    public IConfigService Config { get; }
+
+    public async Task<T> RunCacheSyncExclusiveAsync<T>(Func<Task<T>> action, CancellationToken cancellationToken = default)
+    {
+        await _cacheSyncLock.WaitAsync(cancellationToken).ConfigureAwait(false);
+        try
+        {
+            return await action().ConfigureAwait(false);
+        }
+        finally
+        {
+            _cacheSyncLock.Release();
+        }
+    }
+
+    public async Task<T> RunOrderSyncExclusiveAsync<T>(Func<Task<T>> action, CancellationToken cancellationToken = default)
+    {
+        await _orderSyncLock.WaitAsync(cancellationToken).ConfigureAwait(false);
+        try
+        {
+            return await action().ConfigureAwait(false);
+        }
+        finally
+        {
+            _orderSyncLock.Release();
+        }
+    }
+}

Services/ClientConfigService.cs

@@ -0,0 +1,204 @@
+using System.IO;
+using System.Text.Json;
+using UtopiaCanteenSystem.Data;
+using UtopiaCanteenSystem.Models;
+
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Scanner frontend configuration: backend URL, device/site, admin UI. No HRMS/production credentials.
+/// </summary>
+public sealed class ClientConfigService : IConfigService
+{
+    private readonly string _configPath;
+    private ClientAppConfig _config;
+
+    public ClientConfigService()
+    {
+        DatabasePath.UseClientStorage();
+        _configPath = DatabasePath.GetConfigPath();
+        _config = LoadConfig();
+    }
+
+    public string GetSyncApiEndpoint() => string.Empty;
+    public void SetSyncApiEndpoint(string endpoint) { }
+
+    public bool GetSyncServiceEnabled() => false;
+    public void SetSyncServiceEnabled(bool enabled) { }
+
+    public bool GetScannerConnected() => _config.ScannerConnected;
+    public void SetScannerConnected(bool connected)
+    {
+        _config.ScannerConnected = connected;
+        SaveConfig();
+    }
+
+    public int GetScanIntervalDays() => Math.Clamp(_config.ScanIntervalDays, 0, 365);
+    public void SetScanIntervalDays(int value) { _config.ScanIntervalDays = Math.Clamp(value, 0, 365); SaveConfig(); }
+    public int GetScanIntervalHours() => Math.Clamp(_config.ScanIntervalHours, 0, 23);
+    public void SetScanIntervalHours(int value) { _config.ScanIntervalHours = Math.Clamp(value, 0, 23); SaveConfig(); }
+    public int GetScanIntervalMinutes() => Math.Clamp(_config.ScanIntervalMinutes, 0, 59);
+    public void SetScanIntervalMinutes(int value) { _config.ScanIntervalMinutes = Math.Clamp(value, 0, 59); SaveConfig(); }
+    public int GetScanIntervalSeconds() => Math.Clamp(_config.ScanIntervalSeconds, 0, 59);
+    public void SetScanIntervalSeconds(int value) { _config.ScanIntervalSeconds = Math.Clamp(value, 0, 59); SaveConfig(); }
+
+    public TimeSpan GetScanInterval()
+    {
+        var ts = TimeSpan.FromDays(GetScanIntervalDays()) + TimeSpan.FromHours(GetScanIntervalHours())
+            + TimeSpan.FromMinutes(GetScanIntervalMinutes()) + TimeSpan.FromSeconds(GetScanIntervalSeconds());
+        return ts > TimeSpan.Zero ? ts : TimeSpan.FromMinutes(1);
+    }
+
+    public string GetAdminCardId() => _config.AdminCardId ?? "ADMIN";
+    public void SetAdminCardId(string cardId) { _config.AdminCardId = cardId ?? string.Empty; SaveConfig(); }
+
+    public string GetSiteId() => _config.SiteId ?? string.Empty;
+    public void SetSiteId(string siteId) { _config.SiteId = siteId ?? string.Empty; SaveConfig(); }
+
+    public void ApplyLocationSiteIdFromAuth(string? locationSiteId)
+    {
+        if (string.IsNullOrWhiteSpace(locationSiteId))
+            return;
+        var digits = new string(locationSiteId.Where(char.IsDigit).ToArray());
+        if (string.IsNullOrEmpty(digits))
+            return;
+        _config.SiteId = $"SITE : {digits}";
+        SaveConfig();
+    }
+
+    public string GetDeviceId()
+    {
+        if (!string.IsNullOrWhiteSpace(_config.DeviceId))
+            return _config.DeviceId.Trim();
+
+        _config.DeviceId = ResolveMachineDeviceId();
+        SaveConfig();
+        return _config.DeviceId;
+    }
+
+    public void SetDeviceId(string deviceId)
+    {
+        _config.DeviceId = string.IsNullOrWhiteSpace(deviceId)
+            ? ResolveMachineDeviceId()
+            : deviceId.Trim();
+        SaveConfig();
+    }
+
+    public bool GetRememberAdminCredentials() => _config.RememberAdminCredentials;
+    public void SetRememberAdminCredentials(bool remember) { _config.RememberAdminCredentials = remember; SaveConfig(); }
+    public string GetSavedAdminUsername() => _config.SavedAdminUsername ?? string.Empty;
+    public void SetSavedAdminUsername(string username) { _config.SavedAdminUsername = username ?? string.Empty; SaveConfig(); }
+    public string GetSavedAdminPassword() => DecryptPassword(_config.SavedAdminPasswordProtected ?? string.Empty);
+    public void SetSavedAdminPassword(string password) { _config.SavedAdminPasswordProtected = EncryptPassword(password ?? string.Empty); SaveConfig(); }
+
+    public string GetMySqlConnectionString() => string.Empty;
+    public void SetMySqlConnectionString(string connectionString) { }
+
+    public string GetHrmsLookupConnectionString() => string.Empty;
+    public void SetHrmsLookupConnectionString(string connectionString) { }
+
+    public DateTime? GetLastEmployeeRfidCacheSyncUtc() => null;
+    public void SetLastEmployeeRfidCacheSyncUtc(DateTime utc) { }
+
+    public DateTime? GetLastMealMenuCacheSyncUtc() => null;
+    public void SetLastMealMenuCacheSyncUtc(DateTime utc) { }
+
+    public AppMode GetAppMode() => AppMode.Client;
+    public void SetAppMode(AppMode mode) { }
+
+    public string GetCentralServerBaseUrl() => GetBackendBaseUrl();
+    public void SetCentralServerBaseUrl(string url) => SetBackendBaseUrl(url);
+
+    public string GetBackendBaseUrl() => (_config.BackendBaseUrl ?? string.Empty).TrimEnd('/');
+
+    public void SetBackendBaseUrl(string url)
+    {
+        _config.BackendBaseUrl = (url ?? string.Empty).Trim().TrimEnd('/');
+        SaveConfig();
+    }
+
+    public string GetLocalServerListenUrls() => string.Empty;
+    public void SetLocalServerListenUrls(string urls) { }
+
+    private ClientAppConfig LoadConfig()
+    {
+        try
+        {
+            if (!File.Exists(_configPath))
+                return new ClientAppConfig { BackendBaseUrl = "http://localhost:5000" };
+            var json = File.ReadAllText(_configPath);
+            return JsonSerializer.Deserialize<ClientAppConfig>(json) ?? new ClientAppConfig();
+        }
+        catch
+        {
+            return new ClientAppConfig();
+        }
+    }
+
+    private void SaveConfig()
+    {
+        try
+        {
+            var json = JsonSerializer.Serialize(_config, new JsonSerializerOptions { WriteIndented = true });
+            File.WriteAllText(_configPath, json);
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "ClientConfigService.SaveConfig");
+        }
+    }
+
+    private static string ResolveMachineDeviceId()
+    {
+        var machineName = Environment.MachineName;
+        return string.IsNullOrWhiteSpace(machineName)
+            ? Guid.NewGuid().ToString("N")
+            : machineName.Trim();
+    }
+
+    private static string EncryptPassword(string plain)
+    {
+        if (string.IsNullOrEmpty(plain)) return string.Empty;
+        try
+        {
+            var bytes = System.Text.Encoding.UTF8.GetBytes(plain);
+            var protectedBytes = System.Security.Cryptography.ProtectedData.Protect(bytes, null, System.Security.Cryptography.DataProtectionScope.CurrentUser);
+            return Convert.ToBase64String(protectedBytes);
+        }
+        catch
+        {
+            return string.Empty;
+        }
+    }
+
+    private static string DecryptPassword(string protectedBase64)
+    {
+        if (string.IsNullOrEmpty(protectedBase64)) return string.Empty;
+        try
+        {
+            var protectedBytes = Convert.FromBase64String(protectedBase64);
+            var bytes = System.Security.Cryptography.ProtectedData.Unprotect(protectedBytes, null, System.Security.Cryptography.DataProtectionScope.CurrentUser);
+            return System.Text.Encoding.UTF8.GetString(bytes);
+        }
+        catch
+        {
+            return string.Empty;
+        }
+    }
+
+    private sealed class ClientAppConfig
+    {
+        public string? BackendBaseUrl { get; set; }
+        public bool ScannerConnected { get; set; }
+        public int ScanIntervalDays { get; set; }
+        public int ScanIntervalHours { get; set; }
+        public int ScanIntervalMinutes { get; set; }
+        public int ScanIntervalSeconds { get; set; } = 5;
+        public string? AdminCardId { get; set; }
+        public string? SiteId { get; set; }
+        public string? DeviceId { get; set; }
+        public bool RememberAdminCredentials { get; set; }
+        public string? SavedAdminUsername { get; set; }
+        public string? SavedAdminPasswordProtected { get; set; }
+    }
+}

Services/ConfigConnectionHelper.cs

@@ -0,0 +1,17 @@
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Resolves the effective HRMS/UIND MySQL connection: explicit HRMS lookup string when set,
+/// otherwise the production <see cref="IConfigService.GetMySqlConnectionString"/> value.
+/// </summary>
+public static class ConfigConnectionHelper
+{
+    public static string GetHrmsOrProductionConnectionString(string? hrmsLookupConnectionString, string? mySqlConnectionString)
+    {
+        var hrms = (hrmsLookupConnectionString ?? string.Empty).Trim();
+        if (!string.IsNullOrWhiteSpace(hrms))
+            return hrms;
+
+        return (mySqlConnectionString ?? string.Empty).Trim();
+    }
+}

Services/ConfigService.cs

@@ -4,6 +4,7 @@ using System.Security.Cryptography;
 using System.Text;
 using System.Text.Json;
 using UtopiaCanteenSystem.Data;
+using UtopiaCanteenSystem.Models;
 
 namespace UtopiaCanteenSystem.Services;
 
@@ -128,23 +129,30 @@ public class ConfigService : IConfigService
 
     public string GetDeviceId()
     {
-        //var id = _config.DeviceId ?? string.Empty;
+        if (!string.IsNullOrWhiteSpace(_config.DeviceId))
-        var id = Environment.MachineName;
+            return _config.DeviceId.Trim();
-        if (string.IsNullOrWhiteSpace(id))
+
-        {
+        _config.DeviceId = ResolveMachineDeviceId();
-            id = Guid.NewGuid().ToString("N");
-            _config.DeviceId = id;
         SaveConfig();
-        }
+        return _config.DeviceId;
-        return id;
     }
 
     public void SetDeviceId(string deviceId)
     {
-        _config.DeviceId = deviceId ?? string.Empty;
+        _config.DeviceId = string.IsNullOrWhiteSpace(deviceId)
+            ? ResolveMachineDeviceId()
+            : deviceId.Trim();
         SaveConfig();
     }
 
+    private static string ResolveMachineDeviceId()
+    {
+        var machineName = Environment.MachineName;
+        return string.IsNullOrWhiteSpace(machineName)
+            ? Guid.NewGuid().ToString("N")
+            : machineName.Trim();
+    }
+
     public bool GetRememberAdminCredentials() => _config.RememberAdminCredentials;
 
     public void SetRememberAdminCredentials(bool remember)
@@ -217,17 +225,10 @@ public class ConfigService : IConfigService
         SaveConfig();
     }
 
-    //public string GetHrmsLookupConnectionString() => (_config.HrmsLookupConnectionString ?? string.Empty).Trim();
+    public string GetHrmsLookupConnectionString() =>
-
+        ConfigConnectionHelper.GetHrmsOrProductionConnectionString(
-    public string GetHrmsLookupConnectionString()
+            _config.HrmsLookupConnectionString,
-    {
+            _config.MySqlConnectionString);
-        var hrms = (_config.HrmsLookupConnectionString ?? string.Empty).Trim();
-        if (!string.IsNullOrWhiteSpace(hrms))
-            return hrms;
-
-        // fallback to production/AWS connection string
-        return GetMySqlConnectionString();
-    }
 
     public void SetHrmsLookupConnectionString(string connectionString)
     {
@@ -235,6 +236,89 @@ public class ConfigService : IConfigService
         SaveConfig();
     }
 
+    public DateTime? GetLastEmployeeRfidCacheSyncUtc() => _config.LastEmployeeRfidCacheSyncUtc;
+
+    public void SetLastEmployeeRfidCacheSyncUtc(DateTime utc)
+    {
+        _config.LastEmployeeRfidCacheSyncUtc = utc;
+        SaveConfig();
+    }
+
+    public DateTime? GetLastMealMenuCacheSyncUtc() => _config.LastMealMenuCacheSyncUtc;
+
+    public void SetLastMealMenuCacheSyncUtc(DateTime utc)
+    {
+        _config.LastMealMenuCacheSyncUtc = utc;
+        SaveConfig();
+    }
+
+    public AppMode GetAppMode()
+    {
+        var raw = (_config.AppMode ?? string.Empty).Trim();
+        if (raw.Equals("Client", StringComparison.OrdinalIgnoreCase))
+            return AppMode.Client;
+        return AppMode.Server;
+    }
+
+    public void SetAppMode(AppMode mode)
+    {
+        _config.AppMode = mode == AppMode.Client ? "Client" : "Server";
+        SaveConfig();
+    }
+
+    public string GetCentralServerBaseUrl() => (_config.CentralServerBaseUrl ?? string.Empty).Trim();
+
+    public void SetCentralServerBaseUrl(string url)
+    {
+        var v = url?.Trim() ?? string.Empty;
+        _config.CentralServerBaseUrl = v;
+        _config.BackendBaseUrl = v;
+        SaveConfig();
+    }
+
+    public string GetLocalServerListenUrls()
+    {
+        var u = (_config.LocalServerListenUrls ?? string.Empty).Trim();
+        return string.IsNullOrEmpty(u) ? "http://0.0.0.0:5000" : u;
+    }
+
+    public void SetLocalServerListenUrls(string urls)
+    {
+        _config.LocalServerListenUrls = urls?.Trim() ?? string.Empty;
+        SaveConfig();
+    }
+
+    public string GetBackendBaseUrl()
+    {
+        if (GetAppMode() == AppMode.Server)
+            return DeriveLocalhostApiBaseUrl(GetLocalServerListenUrls());
+
+        var url = (_config.BackendBaseUrl ?? string.Empty).Trim();
+        if (!string.IsNullOrEmpty(url))
+            return url.TrimEnd('/');
+
+        return GetCentralServerBaseUrl().TrimEnd('/');
+    }
+
+    private static string DeriveLocalhostApiBaseUrl(string listenUrls)
+    {
+        var first = (listenUrls ?? string.Empty)
+            .Split(new[] { ';', ',' }, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
+            .FirstOrDefault() ?? "http://0.0.0.0:5000";
+
+        first = first.Trim().TrimEnd('/');
+        if (first.Contains("0.0.0.0", StringComparison.Ordinal))
+            first = first.Replace("0.0.0.0", "localhost", StringComparison.Ordinal);
+        if (first.Contains('+'))
+            first = first.Replace("+", "localhost", StringComparison.Ordinal);
+
+        if (!first.StartsWith("http://", StringComparison.OrdinalIgnoreCase) &&
+            !first.StartsWith("https://", StringComparison.OrdinalIgnoreCase))
+            first = "http://" + first;
+
+        return first;
+    }
+
     private AppConfig LoadConfig()
     {
         try
@@ -251,6 +335,8 @@ public class ConfigService : IConfigService
            var json = File.ReadAllText(_configPath);
            var config = JsonSerializer.Deserialize<AppConfig>(json);
            config ??= new AppConfig();
+            if (string.IsNullOrWhiteSpace(config.BackendBaseUrl) && !string.IsNullOrWhiteSpace(config.CentralServerBaseUrl))
+                config.BackendBaseUrl = config.CentralServerBaseUrl;
             MigrateScanIntervalFromSecondsIfNeeded(config);
             var changed = EnsureConnectionStringDefaults(config);
             if (changed)
@@ -392,5 +478,20 @@ public class ConfigService : IConfigService
 
         // Local HRMS MySQL for employee lookup by RFID. Separate from production sync.
         public string HrmsLookupConnectionString { get; set; } = string.Empty;
+
+        public DateTime? LastEmployeeRfidCacheSyncUtc { get; set; }
+        public DateTime? LastMealMenuCacheSyncUtc { get; set; }
+
+        /// <summary>Server (default) or Client.</summary>
+        public string AppMode { get; set; } = "Server";
+
+        /// <summary>Legacy name; same as BackendBaseUrl for client PCs.</summary>
+        public string CentralServerBaseUrl { get; set; } = string.Empty;
+
+        /// <summary>Client: remote backend URL. Server: optional override (defaults to localhost from ListenUrls).</summary>
+        public string BackendBaseUrl { get; set; } = string.Empty;
+
+        /// <summary>Central PC: API listen URL(s), e.g. http://0.0.0.0:5000</summary>
+        public string LocalServerListenUrls { get; set; } = "http://0.0.0.0:5000";
     }
 }

Services/DbMealSessionResolver.cs

@@ -1,24 +1,41 @@
+using Microsoft.EntityFrameworkCore;
+using UtopiaCanteenSystem.Data;
 using UtopiaCanteenSystem.Models;
 
 namespace UtopiaCanteenSystem.Services;
 
 /// <summary>
-/// Resolves current meal session from production (MySQL meal_schedule). Caches schedules per site for 60 seconds.
+/// Resolves current meal session from local SQLite <c>meal_schedule_cache</c>.
-/// No SQLite; scan validation uses production data only.
 /// </summary>
 public class DbMealSessionResolver : IMealSessionResolver
 {
-    private readonly IMealScheduleService _mealScheduleService;
+    public const string OfflineCacheMissingMessage =
+        "Meal schedule/menu cache not found. Please sync once while online.";
+
+    private readonly IDbContextFactory<AppDbContext> _dbFactory;
     private readonly TimeSpan _cacheTtl = TimeSpan.FromSeconds(60);
 
     private readonly Dictionary<string, (List<MealSchedule> Schedules, DateTime ExpiryUtc)> _cache = new(StringComparer.OrdinalIgnoreCase);
     private readonly object _cacheLock = new();
 
-    public DbMealSessionResolver(IMealScheduleService mealScheduleService)
+    public DbMealSessionResolver(IDbContextFactory<AppDbContext> dbFactory)
     {
-        _mealScheduleService = mealScheduleService;
+        _dbFactory = dbFactory;
     }
 
+    public bool IsScheduleCacheAvailable()
+    {
+        using var db = _dbFactory.CreateDbContext();
+        return db.MealScheduleCache.Any();
+    }
+
+    public bool IsMenuCacheAvailable()
+    {
+        using var db = _dbFactory.CreateDbContext();
+        return db.MenuItemCache.Any() && db.LunchMenuWeekCache.Any();
+    }
+
+    public bool IsOfflineMealDataAvailable() => IsScheduleCacheAvailable() && IsMenuCacheAvailable();
 
     private static MealSession MapMealNameToSession(string? mealName)
     {
@@ -39,49 +56,9 @@ public class DbMealSessionResolver : IMealSessionResolver
         };
     }
 
-
-    /// <inheritdoc />
-    //public MealSession GetCurrentSession(DateTime nowLocal, string siteId)
-    //{
-    //    var normalizedSite = (siteId ?? string.Empty).Trim();
-    //    if (string.IsNullOrEmpty(normalizedSite))
-    //        normalizedSite = "01";
-    //    if (normalizedSite.Length == 1 && char.IsDigit(normalizedSite[0]))
-    //        normalizedSite = normalizedSite.PadLeft(2, '0');
-
-    //    var schedules = GetSchedulesForSiteCached(normalizedSite);
-    //    var t = nowLocal.TimeOfDay;
-
-    //    //foreach (var s in schedules)
-    //    //{
-    //    //    if (!TryParseTime(s.StartTime, out var start) || !TryParseTime(s.EndTime, out var end))
-    //    //        continue;
-    //    //    if (t >= start && t < end)
-    //    //        return (MealSession)s.MealSession;
-    //    //}
-    //    foreach (var s in schedules)
-    //    {
-    //        if (!TryParseTime(s.StartTime, out var start) || !TryParseTime(s.EndTime, out var end))
-    //            continue;
-
-    //        if (t >= start && t < end)
-    //            return MapMealNameToSession(s.MealName);
-    //    }
-
-    //    return MealSession.None;
-    //}
-
-
-
-
     public ResolvedMealSession? GetCurrentSession(DateTime nowLocal, string siteId)
     {
-        var normalizedSite = (siteId ?? string.Empty).Trim();
+        var normalizedSite = SiteIdHelper.NormalizeSiteId(siteId);
-        if (string.IsNullOrEmpty(normalizedSite))
-            normalizedSite = "01";
-        if (normalizedSite.Length == 1 && char.IsDigit(normalizedSite[0]))
-            normalizedSite = normalizedSite.PadLeft(2, '0');
-
         var schedules = GetSchedulesForSiteCached(normalizedSite);
         var t = nowLocal.TimeOfDay;
 
@@ -106,7 +83,6 @@ public class DbMealSessionResolver : IMealSessionResolver
         return null;
     }
 
-
     private List<MealSchedule> GetSchedulesForSiteCached(string siteId)
     {
         lock (_cacheLock)
@@ -115,7 +91,7 @@ public class DbMealSessionResolver : IMealSessionResolver
                 return entry.Schedules;
         }
 
-        var list = _mealScheduleService.GetActiveSchedulesForSite(siteId).ToList();
+        var list = LoadSchedulesForSiteFromCache(siteId);
 
         lock (_cacheLock)
         {
@@ -125,6 +101,35 @@ public class DbMealSessionResolver : IMealSessionResolver
         return list;
     }
 
+    private List<MealSchedule> LoadSchedulesForSiteFromCache(string siteId)
+    {
+        var siteIdInt = SiteIdHelper.ToInt(siteId);
+        using var db = _dbFactory.CreateDbContext();
+
+        var rows = db.MealScheduleCache
+            .AsNoTracking()
+            .Where(x => x.LocationSiteId == siteIdInt)
+            .OrderBy(x => x.StartTime)
+            .ToList();
+
+        return rows.Select(MapToMealSchedule).ToList();
+    }
+
+    private static MealSchedule MapToMealSchedule(MealScheduleCache row)
+    {
+        return new MealSchedule
+        {
+            Id = row.HrmsId,
+            MealName = row.MealName,
+            LocationSiteId = SiteIdHelper.ToDisplayString(row.LocationSiteId),
+            StartTime = row.StartTime,
+            EndTime = row.EndTime,
+            CreatedAt = row.CreatedAt ?? DateTime.MinValue,
+            UpdatedAt = row.UpdatedAt ?? DateTime.MinValue,
+            IsActive = true
+        };
+    }
+
     private static bool TryParseTime(string value, out TimeSpan time)
     {
         time = TimeSpan.Zero;

Services/EmployeeLookupService.cs

@@ -1,77 +1,45 @@
+using Microsoft.EntityFrameworkCore;
 using MySqlConnector;
+using UtopiaCanteenSystem.Data;
 using UtopiaCanteenSystem.Models;
 
 namespace UtopiaCanteenSystem.Services;
 
 /// <summary>
-/// Looks up employee from local HRMS MySQL: employee_rfid_tag.manufacturer_serial → employee (parent_document_id = serial_number) → department.
+/// Looks up employee by RFID from local SQLite <c>employee_rfid_tag_cache</c> (synced from production HRMS).
-/// Uses IConfigService.GetHrmsLookupConnectionString(); separate from production sync connection.
+/// Menu authorization and admin site lookup still use HRMS when configured.
 /// </summary>
 public class EmployeeLookupService : IEmployeeLookupService
 {
+  private readonly IDbContextFactory<AppDbContext> _dbFactory;
   private readonly IConfigService _configService;
 
-    public EmployeeLookupService(IConfigService configService)
+  public EmployeeLookupService(IDbContextFactory<AppDbContext> dbFactory, IConfigService configService)
   {
+    _dbFactory = dbFactory;
     _configService = configService;
   }
 
   /// <inheritdoc />
   public async Task<HrmsEmployeeInfo?> GetEmployeeByRfidAsync(string rfid, CancellationToken cancellationToken = default)
-    
   {
-        var connectionString = _configService.GetHrmsLookupConnectionString();
+    var cardId = rfid?.Trim() ?? string.Empty;
-        if (string.IsNullOrWhiteSpace(connectionString))
+    if (string.IsNullOrEmpty(cardId))
       return null;
 
-        const string sql = @"
+    await using var db = await _dbFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
-            SELECT 
-              e.id AS parent_document_id,
-              e.serial_number AS employee_id,
-              e.concatenated_name AS first_name,
-              '' AS middle_name,
-              r.uind_serial AS uind_serial,
-              r.function_id AS function_id,
-              r.department_id AS tag_department_id,
-              r.date_time_created AS tag_date_time_created,
-              r.created_by AS tag_created_by,
-              d.title AS department_title,
-              d.department_type,
-              r.location_site_id AS location_site_id,
-              r.grade_type AS grade_type
-            FROM employee_rfid_tag r
-            JOIN employee e ON e.id = r.parent_document_id
-            LEFT JOIN department d ON d.id = e.department_id
-            WHERE r.manufacturer_serial = @rfid
-              AND r.parent_document_type = 'Employee'
-            LIMIT 1";
 
-        await using var conn = new MySqlConnection(connectionString);
+    var tag = await db.EmployeeRfidTagCache
-        await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
+      .AsNoTracking()
-        await using var cmd = new MySqlCommand(sql, conn);
+      .Where(x => x.ManufacturerSerial == cardId)
-        cmd.Parameters.AddWithValue("@rfid", rfid?.Trim() ?? string.Empty);
+      .Where(x => x.ParentDocumentType == "Employee")
+      .FirstOrDefaultAsync(cancellationToken)
+      .ConfigureAwait(false);
 
-        await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
+    if (tag == null)
-        if (!await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
       return null;
 
-        var parentDocumentId = GetString(reader, 0);
+    return MapToHrmsEmployeeInfo(tag);
-        return new HrmsEmployeeInfo
-        {
-            ParentDocumentId = parentDocumentId,
-            EmployeeId = GetString(reader, 1),
-            FirstName = GetString(reader, 2),
-            MiddleName = GetString(reader, 3),
-            UindSerial = GetString(reader, 4),
-            FunctionId = GetInt(reader, 5),
-            DepartmentId = GetInt(reader, 6),
-            TagCreatedAtUtc = GetDateTimeNullable(reader, 7),
-            TagCreatedBy = GetString(reader, 8),
-            DepartmentTitle = GetString(reader, 9),
-            DepartmentType = GetString(reader, 10),
-            LocationSiteId = GetString(reader, 11),
-            GradeType = GetString(reader, 12)
-        };
   }
 
   /// <inheritdoc />
@@ -81,30 +49,21 @@ public class EmployeeLookupService : IEmployeeLookupService
     if (string.IsNullOrEmpty(serial))
       return null;
 
-        var connectionString = _configService.GetHrmsLookupConnectionString();
+    await using var db = await _dbFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
-        if (string.IsNullOrWhiteSpace(connectionString))
-            return null;
 
-        const string sql = @"
+    var siteId = await db.EmployeeRfidTagCache
-            SELECT location_site_id
+      .AsNoTracking()
-            FROM employee
+      .Where(x => x.ParentDocumentType == "Employee")
-            WHERE serial_number = @serial
+      .Where(x => x.EmployeeSerialNumber == serial)
-            LIMIT 1";
+      .Where(x => !string.IsNullOrEmpty(x.LocationSiteId))
+      .Select(x => x.LocationSiteId)
+      .FirstOrDefaultAsync(cancellationToken)
+      .ConfigureAwait(false);
 
-        await using var conn = new MySqlConnection(connectionString);
+    if (!string.IsNullOrWhiteSpace(siteId))
-        await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
+      return siteId.Trim();
-        await using var cmd = new MySqlCommand(sql, conn);
-        cmd.Parameters.AddWithValue("@serial", serial);
 
-        await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
+    return await GetLocationSiteIdFromHrmsAsync(serial, cancellationToken).ConfigureAwait(false);
-        if (!await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
-            return null;
-
-        if (reader.IsDBNull(0))
-            return null;
-
-        var raw = reader.GetValue(0)?.ToString()?.Trim();
-        return string.IsNullOrEmpty(raw) ? null : raw;
   }
 
   /// <inheritdoc />
@@ -136,42 +95,51 @@ public class EmployeeLookupService : IEmployeeLookupService
     return exists != null && exists != DBNull.Value;
   }
 
-    private static string GetString(MySqlDataReader reader, int ordinal)
+  private static HrmsEmployeeInfo MapToHrmsEmployeeInfo(EmployeeRfidTagCache tag)
   {
-        if (reader.IsDBNull(ordinal)) return string.Empty;
+    return new HrmsEmployeeInfo
-        var v = reader.GetValue(ordinal);
+    {
-        return v?.ToString() ?? string.Empty;
+      ParentDocumentId = tag.ParentDocumentId,
+      EmployeeId = tag.EmployeeSerialNumber,
+      FirstName = tag.EmployeeConcatenatedName,
+      MiddleName = string.Empty,
+      UindSerial = tag.UindSerial,
+      FunctionId = tag.FunctionId,
+      DepartmentId = tag.DepartmentId,
+      TagCreatedAtUtc = tag.DateTimeCreated,
+      TagCreatedBy = tag.CreatedBy,
+      DepartmentTitle = tag.DepartmentTitle,
+      DepartmentType = tag.DepartmentType,
+      LocationSiteId = tag.LocationSiteId,
+      GradeType = tag.GradeType
+    };
   }
 
-    private static int GetInt(MySqlDataReader reader, int ordinal)
+  private async Task<string?> GetLocationSiteIdFromHrmsAsync(string serial, CancellationToken cancellationToken)
   {
-        try
+    var connectionString = _configService.GetHrmsLookupConnectionString();
-        {
+    if (string.IsNullOrWhiteSpace(connectionString))
-            if (reader.IsDBNull(ordinal)) return 0;
+      return null;
-            var v = reader.GetValue(ordinal);
-            if (v is int i) return i;
-            if (v is long l) return (int)l;
-            return int.TryParse(v?.ToString(), out var parsed) ? parsed : 0;
-        }
-        catch
-        {
-            return 0;
-        }
-    }
 
-    private static DateTime? GetDateTimeNullable(MySqlDataReader reader, int ordinal)
+    const string sql = @"
-    {
+            SELECT location_site_id
-        try
+            FROM employee
-        {
+            WHERE serial_number = @serial
-            if (reader.IsDBNull(ordinal)) return null;
+            LIMIT 1";
-            var v = reader.GetValue(ordinal);
+
-            if (v is DateTime dt) return dt;
+    await using var conn = new MySqlConnection(connectionString);
-            if (DateTime.TryParse(v?.ToString(), out var parsed)) return parsed;
+    await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
+    await using var cmd = new MySqlCommand(sql, conn);
+    cmd.Parameters.AddWithValue("@serial", serial);
+
+    await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
+    if (!await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
       return null;
-        }
+
-        catch
+    if (reader.IsDBNull(0))
-        {
       return null;
-        }
+
+    var raw = reader.GetValue(0)?.ToString()?.Trim();
+    return string.IsNullOrEmpty(raw) ? null : raw;
   }
 }

Services/EmployeeRfidTagSyncService.cs

@@ -0,0 +1,266 @@
+using Microsoft.EntityFrameworkCore;
+using MySqlConnector;
+using UtopiaCanteenSystem.Data;
+using UtopiaCanteenSystem.Models;
+using UtopiaCanteenSystem.Services.Logging;
+
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Pulls <c>hrms.employee_rfid_tag</c> from production HRMS and upserts into local SQLite.
+/// HRMS is only accessed here—not during RFID scan.
+/// </summary>
+public class EmployeeRfidTagSyncService : IEmployeeRfidTagSyncService
+{
+  private readonly IDbContextFactory<AppDbContext> _dbFactory;
+  private readonly IConfigService _configService;
+
+  public EmployeeRfidTagSyncService(IDbContextFactory<AppDbContext> dbFactory, IConfigService configService)
+  {
+    _dbFactory = dbFactory;
+    _configService = configService;
+  }
+
+  public async Task<EmployeeRfidTagSyncResult> SyncAllAsync(CancellationToken cancellationToken = default)
+  {
+    FileLogger.Info("CacheSync", "Employee RFID sync started.");
+
+    var connectionString = _configService.GetHrmsLookupConnectionString();
+    if (string.IsNullOrWhiteSpace(connectionString))
+    {
+      FileLogger.Warn("CacheSync", "Employee RFID sync skipped. MySQL connection string is not configured.");
+      return new EmployeeRfidTagSyncResult
+      {
+        Success = false,
+        ErrorMessage = "MySQL connection string is not configured."
+      };
+    }
+
+    List<HrmsRfidTagRow> rows;
+    try
+    {
+      rows = await FetchAllFromHrmsAsync(connectionString, cancellationToken).ConfigureAwait(false);
+      FileLogger.Info("CacheSync", $"Employee RFID rows fetched from HRMS/UIND. RowsFetched={rows.Count}.");
+    }
+    catch (Exception ex)
+    {
+      Logger.Log(ex, "EmployeeRfidTagSyncService.SyncAllAsync");
+      FileLogger.Error("CacheSync", "Employee RFID sync failed while fetching from HRMS/UIND.", ex);
+      return new EmployeeRfidTagSyncResult
+      {
+        Success = false,
+        ErrorMessage = ex.Message
+      };
+    }
+
+    var syncedAt = DateTime.UtcNow;
+    var upserted = 0;
+
+    await using var db = await _dbFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
+
+    foreach (var row in rows)
+    {
+      if (row.HrmsId <= 0)
+        continue;
+
+      var manufacturerSerial = row.ManufacturerSerial?.Trim() ?? string.Empty;
+
+      EmployeeRfidTagCache? existing = await db.EmployeeRfidTagCache
+        .FirstOrDefaultAsync(x => x.HrmsId == row.HrmsId, cancellationToken)
+        .ConfigureAwait(false);
+
+      if (existing == null && !string.IsNullOrEmpty(manufacturerSerial))
+      {
+        existing = await db.EmployeeRfidTagCache
+          .FirstOrDefaultAsync(x => x.ManufacturerSerial == manufacturerSerial, cancellationToken)
+          .ConfigureAwait(false);
+      }
+
+      if (existing == null)
+      {
+        db.EmployeeRfidTagCache.Add(MapToEntity(row, syncedAt));
+      }
+      else
+      {
+        ApplyRow(existing, row, syncedAt);
+      }
+
+      upserted++;
+    }
+
+    await db.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
+    _configService.SetLastEmployeeRfidCacheSyncUtc(syncedAt);
+
+    FileLogger.Info(
+      "CacheSync",
+      $"Employee RFID sync completed. RowsFetched={rows.Count}, Upserted={upserted}.");
+
+    return new EmployeeRfidTagSyncResult
+    {
+      Success = true,
+      UpsertedCount = upserted
+    };
+  }
+
+  private static async Task<List<HrmsRfidTagRow>> FetchAllFromHrmsAsync(
+    string connectionString,
+    CancellationToken cancellationToken)
+  {
+    const string sql = @"
+            SELECT
+              r.id,
+              r.manufacturer_serial,
+              r.uind_serial,
+              r.secret,
+              r.parent_document_type,
+              r.parent_document_id,
+              r.date_time_created,
+              r.created_by,
+              r.grade_id,
+              r.grade_type,
+              r.shift_id,
+              r.location_site_id,
+              r.rfid_location_site_id,
+              r.function_id,
+              r.department_id,
+              r.reporting_manager_ids,
+              e.serial_number AS employee_serial_number,
+              e.concatenated_name AS employee_concatenated_name,
+              d.title AS department_title,
+              d.department_type AS department_type
+            FROM employee_rfid_tag r
+            LEFT JOIN employee e ON e.id = r.parent_document_id
+              AND r.parent_document_type = 'Employee'
+            LEFT JOIN department d ON d.id = e.department_id";
+
+    var rows = new List<HrmsRfidTagRow>();
+
+    await using var conn = new MySqlConnection(connectionString);
+    await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
+    await using var cmd = new MySqlCommand(sql, conn);
+    await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
+
+    while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
+    {
+      rows.Add(new HrmsRfidTagRow
+      {
+        HrmsId = GetInt64(reader, 0),
+        ManufacturerSerial = GetString(reader, 1),
+        UindSerial = GetString(reader, 2),
+        Secret = GetString(reader, 3),
+        ParentDocumentType = GetString(reader, 4),
+        ParentDocumentId = GetString(reader, 5),
+        DateTimeCreated = GetDateTimeNullable(reader, 6),
+        CreatedBy = GetString(reader, 7),
+        GradeId = GetIntNullable(reader, 8),
+        GradeType = GetString(reader, 9),
+        ShiftId = GetIntNullable(reader, 10),
+        LocationSiteId = GetString(reader, 11),
+        RfidLocationSiteId = GetString(reader, 12),
+        FunctionId = GetInt(reader, 13),
+        DepartmentId = GetInt(reader, 14),
+        ReportingManagerIds = GetString(reader, 15),
+        EmployeeSerialNumber = GetString(reader, 16),
+        EmployeeConcatenatedName = GetString(reader, 17),
+        DepartmentTitle = GetString(reader, 18),
+        DepartmentType = GetString(reader, 19)
+      });
+    }
+
+    return rows;
+  }
+
+  private static EmployeeRfidTagCache MapToEntity(HrmsRfidTagRow row, DateTime syncedAtUtc)
+  {
+    var entity = new EmployeeRfidTagCache();
+    ApplyRow(entity, row, syncedAtUtc);
+    return entity;
+  }
+
+  private static void ApplyRow(EmployeeRfidTagCache entity, HrmsRfidTagRow row, DateTime syncedAtUtc)
+  {
+    entity.HrmsId = row.HrmsId;
+    entity.ManufacturerSerial = row.ManufacturerSerial?.Trim() ?? string.Empty;
+    entity.UindSerial = row.UindSerial ?? string.Empty;
+    entity.Secret = row.Secret ?? string.Empty;
+    entity.ParentDocumentType = row.ParentDocumentType ?? string.Empty;
+    entity.ParentDocumentId = row.ParentDocumentId ?? string.Empty;
+    entity.DateTimeCreated = row.DateTimeCreated;
+    entity.CreatedBy = row.CreatedBy ?? string.Empty;
+    entity.GradeId = row.GradeId;
+    entity.GradeType = row.GradeType ?? string.Empty;
+    entity.ShiftId = row.ShiftId;
+    entity.LocationSiteId = row.LocationSiteId ?? string.Empty;
+    entity.RfidLocationSiteId = row.RfidLocationSiteId ?? string.Empty;
+    entity.FunctionId = row.FunctionId;
+    entity.DepartmentId = row.DepartmentId;
+    entity.ReportingManagerIds = row.ReportingManagerIds ?? string.Empty;
+    entity.EmployeeSerialNumber = row.EmployeeSerialNumber ?? string.Empty;
+    entity.EmployeeConcatenatedName = row.EmployeeConcatenatedName ?? string.Empty;
+    entity.DepartmentTitle = row.DepartmentTitle ?? string.Empty;
+    entity.DepartmentType = row.DepartmentType ?? string.Empty;
+    entity.LastSyncedAtUtc = syncedAtUtc;
+  }
+
+  private static string GetString(MySqlDataReader reader, int ordinal)
+  {
+    if (reader.IsDBNull(ordinal)) return string.Empty;
+    return reader.GetValue(ordinal)?.ToString() ?? string.Empty;
+  }
+
+  private static int GetInt(MySqlDataReader reader, int ordinal)
+  {
+    if (reader.IsDBNull(ordinal)) return 0;
+    var v = reader.GetValue(ordinal);
+    if (v is int i) return i;
+    if (v is long l) return (int)l;
+    return int.TryParse(v?.ToString(), out var parsed) ? parsed : 0;
+  }
+
+  private static long GetInt64(MySqlDataReader reader, int ordinal)
+  {
+    if (reader.IsDBNull(ordinal)) return 0;
+    var v = reader.GetValue(ordinal);
+    if (v is long l) return l;
+    if (v is int i) return i;
+    return long.TryParse(v?.ToString(), out var parsed) ? parsed : 0;
+  }
+
+  private static int? GetIntNullable(MySqlDataReader reader, int ordinal)
+  {
+    if (reader.IsDBNull(ordinal)) return null;
+    return GetInt(reader, ordinal);
+  }
+
+  private static DateTime? GetDateTimeNullable(MySqlDataReader reader, int ordinal)
+  {
+    if (reader.IsDBNull(ordinal)) return null;
+    var v = reader.GetValue(ordinal);
+    if (v is DateTime dt) return dt;
+    return DateTime.TryParse(v?.ToString(), out var parsed) ? parsed : null;
+  }
+
+  private sealed class HrmsRfidTagRow
+  {
+    public long HrmsId { get; set; }
+    public string ManufacturerSerial { get; set; } = string.Empty;
+    public string UindSerial { get; set; } = string.Empty;
+    public string Secret { get; set; } = string.Empty;
+    public string ParentDocumentType { get; set; } = string.Empty;
+    public string ParentDocumentId { get; set; } = string.Empty;
+    public DateTime? DateTimeCreated { get; set; }
+    public string CreatedBy { get; set; } = string.Empty;
+    public int? GradeId { get; set; }
+    public string GradeType { get; set; } = string.Empty;
+    public int? ShiftId { get; set; }
+    public string LocationSiteId { get; set; } = string.Empty;
+    public string RfidLocationSiteId { get; set; } = string.Empty;
+    public int FunctionId { get; set; }
+    public int DepartmentId { get; set; }
+    public string ReportingManagerIds { get; set; } = string.Empty;
+    public string EmployeeSerialNumber { get; set; } = string.Empty;
+    public string EmployeeConcatenatedName { get; set; } = string.Empty;
+    public string DepartmentTitle { get; set; } = string.Empty;
+    public string DepartmentType { get; set; } = string.Empty;
+  }
+}

Services/EmptyMenuLookupService.cs

@@ -0,0 +1,20 @@
+using UtopiaCanteenSystem.Models;
+
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Client scanner UI: menu data comes from scan API response, not local SQLite/HRMS.
+/// </summary>
+public sealed class EmptyMenuLookupService : IMenuLookupService
+{
+    public Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAsync(int siteIdNumeric, CancellationToken cancellationToken = default) =>
+        Task.FromResult<IReadOnlyList<HrmsMenuItem>>(Array.Empty<HrmsMenuItem>());
+
+    public Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAndDateAsync(
+        int siteIdNumeric,
+        DateTime menuDateLocal,
+        string gradeType,
+        string mealName,
+        CancellationToken cancellationToken = default) =>
+        Task.FromResult<IReadOnlyList<HrmsMenuItem>>(Array.Empty<HrmsMenuItem>());
+}

Services/ICanteenBackendApiClient.cs

@@ -0,0 +1,29 @@
+using UtopiaCanteen.Shared;
+
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// HTTP client for the central canteen backend API (scanner UI and settings).
+/// </summary>
+public interface ICanteenBackendApiClient : IRfidService
+{
+    Task<bool> HealthCheckAsync(CancellationToken cancellationToken = default);
+
+    Task<ManualSyncResponse> SyncCacheNowAsync(CancellationToken cancellationToken = default);
+
+    Task<ManualSyncResponse> SyncOrdersNowAsync(CancellationToken cancellationToken = default);
+
+    Task<CacheStatusResponse?> GetCacheStatusAsync(CancellationToken cancellationToken = default);
+
+    Task<HealthResponse?> GetHealthAsync(CancellationToken cancellationToken = default);
+
+    Task<IReadOnlyList<MealScheduleDto>> GetMealSchedulesAsync(CancellationToken cancellationToken = default);
+
+    Task<long> CreateMealScheduleAsync(MealScheduleDto schedule, CancellationToken cancellationToken = default);
+
+    Task UpdateMealScheduleAsync(MealScheduleDto schedule, CancellationToken cancellationToken = default);
+
+    Task DeleteMealScheduleAsync(long id, CancellationToken cancellationToken = default);
+
+    Task<string?> GetEmployeeLocationSiteAsync(string employeeId, CancellationToken cancellationToken = default);
+}

Services/IConfigService.cs

@@ -1,3 +1,5 @@
+using UtopiaCanteenSystem.Models;
+
 namespace UtopiaCanteenSystem.Services;
 
 /// <summary>
@@ -42,7 +44,30 @@ public interface IConfigService
     string GetMySqlConnectionString();
     void SetMySqlConnectionString(string connectionString);
 
-    /// <summary>Connection string for local HRMS MySQL (employee lookup by RFID). Separate from production sync.</summary>
+    /// <summary>
+    /// MySQL connection for HRMS/UIND (cache sync, employee lookup, lunch_order post).
+    /// Uses <c>HrmsLookupConnectionString</c> when set; otherwise <see cref="GetMySqlConnectionString"/>.
+    /// </summary>
     string GetHrmsLookupConnectionString();
     void SetHrmsLookupConnectionString(string connectionString);
+
+    DateTime? GetLastEmployeeRfidCacheSyncUtc();
+    void SetLastEmployeeRfidCacheSyncUtc(DateTime utc);
+
+    DateTime? GetLastMealMenuCacheSyncUtc();
+    void SetLastMealMenuCacheSyncUtc(DateTime utc);
+
+    AppMode GetAppMode();
+    void SetAppMode(AppMode mode);
+
+    /// <summary>Client mode: central server API base URL (e.g. http://192.168.1.10:5000).</summary>
+    string GetCentralServerBaseUrl();
+    void SetCentralServerBaseUrl(string url);
+
+    /// <summary>Backend API base URL for HTTP calls (client: remote server; server: http://localhost:port).</summary>
+    string GetBackendBaseUrl();
+
+    /// <summary>HttpListener bind URL(s) when <see cref="AppMode.Server"/> (e.g. http://0.0.0.0:5000).</summary>
+    string GetLocalServerListenUrls();
+    void SetLocalServerListenUrls(string urls);
 }

Services/IEmployeeLookupService.cs

@@ -3,13 +3,13 @@ using UtopiaCanteenSystem.Models;
 namespace UtopiaCanteenSystem.Services;
 
 /// <summary>
-/// Looks up employee info from local HRMS MySQL by RFID (manufacturer_serial).
+/// Employee lookup by RFID from local SQLite cache; menu authorization may still use HRMS.
-/// Uses a separate connection from production sync.
 /// </summary>
 public interface IEmployeeLookupService
 {
     /// <summary>
-    /// Finds employee by RFID. Returns null if card is not registered in HRMS.
+    /// Finds employee by RFID (<c>manufacturer_serial</c>) in local <c>employee_rfid_tag_cache</c>.
+    /// Returns null if the card is not in the cache (sync from HRMS first).
     /// </summary>
     Task<HrmsEmployeeInfo?> GetEmployeeByRfidAsync(string rfid, CancellationToken cancellationToken = default);
 

Services/IEmployeeRfidTagSyncService.cs

@@ -0,0 +1,19 @@
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Syncs production <c>hrms.employee_rfid_tag</c> into local SQLite for offline RFID lookup.
+/// </summary>
+public interface IEmployeeRfidTagSyncService
+{
+  /// <summary>
+  /// Fetches all RFID tags from production HRMS and upserts into <c>employee_rfid_tag_cache</c>.
+  /// </summary>
+  Task<EmployeeRfidTagSyncResult> SyncAllAsync(CancellationToken cancellationToken = default);
+}
+
+public sealed class EmployeeRfidTagSyncResult
+{
+  public bool Success { get; init; }
+  public int UpsertedCount { get; init; }
+  public string? ErrorMessage { get; init; }
+}

Services/IMealMenuCacheSyncService.cs

@@ -0,0 +1,19 @@
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Syncs meal schedules and lunch menu tables from production HRMS into local SQLite.
+/// </summary>
+public interface IMealMenuCacheSyncService
+{
+    Task<MealMenuCacheSyncResult> SyncAllAsync(CancellationToken cancellationToken = default);
+}
+
+public sealed class MealMenuCacheSyncResult
+{
+    public bool Success { get; init; }
+    public int MealScheduleCount { get; init; }
+    public int LunchMenuWeekCount { get; init; }
+    public int LunchMenuItemCount { get; init; }
+    public int MenuItemCount { get; init; }
+    public string? ErrorMessage { get; init; }
+}

Services/IMealSessionResolver.cs

@@ -7,9 +7,17 @@ namespace UtopiaCanteenSystem.Services;
 /// </summary>
 public interface IMealSessionResolver
 {
+    /// <summary>True when local <c>meal_schedule_cache</c> has at least one row.</summary>
+    bool IsScheduleCacheAvailable();
+
+    /// <summary>True when local menu cache tables have data.</summary>
+    bool IsMenuCacheAvailable();
+
+    /// <summary>True when both schedule and menu caches are populated.</summary>
+    bool IsOfflineMealDataAvailable();
+
     /// <summary>
-    /// Returns the active meal session for the given local time and site, or MealSession.None if outside all windows.
+    /// Returns the active meal session for the given local time and site, or null if outside all windows.
     /// </summary>
-    //MealSession GetCurrentSession(DateTime nowLocal, string siteId);
     ResolvedMealSession? GetCurrentSession(DateTime nowLocal, string siteId);
 }

Services/IMenuLookupService.cs

@@ -3,7 +3,7 @@ using UtopiaCanteenSystem.Models;
 namespace UtopiaCanteenSystem.Services;
 
 /// <summary>
-/// Fetches lunch menu items from local HRMS by site (lunch_menu_week.location_site_id).
+/// Fetches lunch menu items from local SQLite cache by site (synced from HRMS).
 /// Uses same HRMS connection as employee lookup.
 /// </summary>
 public interface IMenuLookupService

Services/IOfflineCacheSyncService.cs

@@ -0,0 +1,17 @@
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Runs employee RFID and meal/menu offline cache sync jobs (no lunch order production sync).
+/// </summary>
+public interface IOfflineCacheSyncService
+{
+    Task<OfflineCacheSyncResult> SyncEmployeeAndMenuCacheAsync(CancellationToken cancellationToken = default);
+}
+
+public sealed class OfflineCacheSyncResult
+{
+    public bool Success { get; init; }
+    public string? ErrorMessage { get; init; }
+    public EmployeeRfidTagSyncResult? EmployeeSync { get; init; }
+    public MealMenuCacheSyncResult? MealMenuSync { get; init; }
+}

Services/ISyncService.cs

@@ -5,6 +5,6 @@ namespace UtopiaCanteenSystem.Services;
 /// </summary>
 public interface ISyncService
 {
-    /// <summary>Runs one sync: POST unsynced records to API and mark as synced on success.</summary>
+    /// <summary>Runs one sync: POST unsynced records to production/HRMS and mark as synced on success.</summary>
-    Task SyncNowAsync(CancellationToken cancellationToken = default);
+    Task<SyncNowResult> SyncNowAsync(CancellationToken cancellationToken = default);
 }

Services/Logger.cs

@@ -1,53 +1,52 @@
-using System;
 using System.IO;
-using System.Text;
+using UtopiaCanteenSystem.Services.Logging;
 
 namespace UtopiaCanteenSystem.Services;
 
 public static class Logger
 {
-    private static readonly object _lock = new();
-
     public static void Log(Exception ex, string context = "")
     {
         try
         {
-            if (ex == null) return;
+            if (ex == null)
+                return;
 
-            var localAppData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+            if (FileLogger.IsConfigured)
-            var appRoot = Path.Combine(localAppData, "UtopiaCanteenSystem");
-            var logsDir = Path.Combine(appRoot, "Logs");
-            var logFile = Path.Combine(logsDir, "error.log");
-
-            try
-            {
-                if (!Directory.Exists(logsDir))
-                    Directory.CreateDirectory(logsDir);
-            }
-            catch
             {
+                FileLogger.Error(context, ex.Message, ex);
                 return;
             }
 
-            var sb = new StringBuilder();
+            WriteLegacyErrorLog(ex, context);
-            sb.AppendLine($"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}]");
-            if (!string.IsNullOrWhiteSpace(context))
-                sb.AppendLine($"Context: {context}");
-            sb.AppendLine($"Message: {ex.Message}");
-            sb.AppendLine($"StackTrace: {ex.StackTrace}");
-            if (ex.InnerException != null)
-                sb.AppendLine($"InnerException: {ex.InnerException.Message}");
-            sb.AppendLine("----------------------------------------------------");
-
-            lock (_lock)
-            {
-                File.AppendAllText(logFile, sb.ToString());
-            }
         }
         catch
         {
             // never throw from logger
         }
     }
+
+    private static void WriteLegacyErrorLog(Exception ex, string context)
+    {
+        var localAppData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+        var logsDir = Path.Combine(localAppData, "UtopiaCanteenSystem", "Logs");
+        var logFile = Path.Combine(logsDir, "error.log");
+
+        if (!Directory.Exists(logsDir))
+            Directory.CreateDirectory(logsDir);
+
+        var lines = new List<string>
+        {
+            $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}]",
+            string.IsNullOrWhiteSpace(context) ? string.Empty : $"Context: {context}",
+            $"Message: {ex.Message}",
+            $"StackTrace: {ex.StackTrace}"
+        };
+        if (ex.InnerException != null)
+            lines.Add($"InnerException: {ex.InnerException.Message}");
+        lines.Add("----------------------------------------------------");
+
+        File.AppendAllText(logFile, string.Join(Environment.NewLine, lines.Where(l => !string.IsNullOrEmpty(l))) + Environment.NewLine);
+    }
 }
 

Services/Logging/FileLogTarget.cs

@@ -0,0 +1,7 @@
+namespace UtopiaCanteenSystem.Services.Logging;
+
+public enum FileLogTarget
+{
+    Backend,
+    Client
+}

Services/Logging/FileLogger.cs

@@ -0,0 +1,99 @@
+using System.IO;
+using System.Text;
+
+namespace UtopiaCanteenSystem.Services.Logging;
+
+/// <summary>
+/// Thread-safe daily file logger. Never throws to callers.
+/// </summary>
+public static class FileLogger
+{
+    private static readonly object Lock = new();
+    private static FileLogTarget? _target;
+
+    public static bool IsConfigured => _target.HasValue;
+
+    public static void ConfigureBackend() => Configure(FileLogTarget.Backend);
+
+    public static void ConfigureClient() => Configure(FileLogTarget.Client);
+
+    public static void Configure(FileLogTarget target)
+    {
+        _target = target;
+        var dir = GetLogsDirectory();
+        try
+        {
+            Directory.CreateDirectory(dir);
+        }
+        catch
+        {
+            // Ignore
+        }
+
+        Info("FileLogger", $"Logging initialized. Directory={dir}");
+    }
+
+    public static string GetLogsDirectory() =>
+        _target == FileLogTarget.Client
+            ? LogPaths.ClientLogsDirectory
+            : LogPaths.BackendLogsDirectory;
+
+    public static void Debug(string component, string message) => Write("DEBUG", component, message, null);
+
+    public static void Info(string component, string message) => Write("INFO", component, message, null);
+
+    public static void Warn(string component, string message, Exception? ex = null) =>
+        Write("WARN", component, message, ex);
+
+    public static void Error(string component, string message, Exception? ex = null) =>
+        Write("ERROR", component, message, ex);
+
+    private static void Write(string level, string component, string message, Exception? ex)
+    {
+        if (!_target.HasValue)
+            return;
+
+        try
+        {
+            var dir = GetLogsDirectory();
+            var prefix = _target == FileLogTarget.Client ? "client" : "backend";
+            var file = Path.Combine(dir, $"{prefix}-{DateTime.Now:yyyy-MM-dd}.log");
+            var line = FormatLine(level, component, message, ex);
+
+            lock (Lock)
+            {
+                Directory.CreateDirectory(dir);
+                File.AppendAllText(file, line, Encoding.UTF8);
+            }
+        }
+        catch
+        {
+            // Never crash the app because logging failed.
+        }
+    }
+
+    private static string FormatLine(string level, string component, string message, Exception? ex)
+    {
+        var sb = new StringBuilder();
+        sb.Append($"{DateTime.Now:yyyy-MM-dd HH:mm:ss.fff} [{level}] [{component}] {message}");
+        if (ex != null)
+        {
+            sb.AppendLine();
+            sb.Append($"Exception: {ex.GetType().Name}: {ex.Message}");
+            if (!string.IsNullOrWhiteSpace(ex.StackTrace))
+            {
+                sb.AppendLine();
+                sb.Append(ex.StackTrace);
+            }
+
+            if (ex.InnerException != null)
+            {
+                sb.AppendLine();
+                sb.Append($"InnerException: {ex.InnerException.GetType().Name}: {ex.InnerException.Message}");
+            }
+        }
+
+        sb.AppendLine();
+        return sb.ToString();
+    }
+}

Services/Logging/FileLoggerProvider.cs

@@ -0,0 +1,60 @@
+using Microsoft.Extensions.Logging;
+
+namespace UtopiaCanteenSystem.Services.Logging;
+
+public sealed class FileLoggerProvider : ILoggerProvider
+{
+    public ILogger CreateLogger(string categoryName) => new FileLoggerAdapter(categoryName);
+
+    public void Dispose()
+    {
+    }
+
+    private sealed class FileLoggerAdapter : ILogger
+    {
+        private readonly string _category;
+
+        public FileLoggerAdapter(string category) => _category = category;
+
+        public IDisposable? BeginScope<TState>(TState state) where TState : notnull => null;
+
+        public bool IsEnabled(LogLevel logLevel) => logLevel >= LogLevel.Information;
+
+        public void Log<TState>(
+            LogLevel logLevel,
+            EventId eventId,
+            TState state,
+            Exception? exception,
+            Func<TState, Exception?, string> formatter)
+        {
+            if (!IsEnabled(logLevel))
+                return;
+
+            var message = formatter(state, exception);
+            var component = ShortCategory(_category);
+            switch (logLevel)
+            {
+                case LogLevel.Critical:
+                case LogLevel.Error:
+                    FileLogger.Error(component, message, exception);
+                    break;
+                case LogLevel.Warning:
+                    FileLogger.Warn(component, message, exception);
+                    break;
+                case LogLevel.Debug:
+                case LogLevel.Trace:
+                    FileLogger.Debug(component, message);
+                    break;
+                default:
+                    FileLogger.Info(component, message);
+                    break;
+            }
+        }
+
+        private static string ShortCategory(string category)
+        {
+            var idx = category.LastIndexOf('.');
+            return idx >= 0 ? category[(idx + 1)..] : category;
+        }
+    }
+}

Services/Logging/InteractiveUserPath.cs

@@ -0,0 +1,58 @@
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace UtopiaCanteenSystem.Services.Logging;
+
+/// <summary>
+/// Resolves the logged-on Windows user's profile paths when the app runs as a service (SYSTEM).
+/// </summary>
+public static class InteractiveUserPath
+{
+    public static string? TryGetLocalAppDataPath()
+    {
+        var profile = TryGetProfileDirectory();
+        if (string.IsNullOrWhiteSpace(profile))
+            return null;
+
+        var localAppData = Path.Combine(profile, "AppData", "Local");
+        return Directory.Exists(localAppData) ? localAppData : null;
+    }
+
+    private static string? TryGetProfileDirectory()
+    {
+        var sessionId = WTSGetActiveConsoleSessionId();
+        if (sessionId == 0xFFFFFFFF)
+            return null;
+
+        if (!WTSQueryUserToken(sessionId, out var userToken) || userToken == IntPtr.Zero)
+            return null;
+
+        try
+        {
+            var sb = new StringBuilder(512);
+            var size = sb.Capacity;
+            if (!GetUserProfileDirectory(userToken, sb, ref size, out _))
+                return null;
+
+            var path = sb.ToString();
+            return string.IsNullOrWhiteSpace(path) ? null : path;
+        }
+        finally
+        {
+            CloseHandle(userToken);
+        }
+    }
+
+    [DllImport("kernel32.dll")]
+    private static extern uint WTSGetActiveConsoleSessionId();
+
+    [DllImport("wtsapi32.dll", SetLastError = true)]
+    private static extern bool WTSQueryUserToken(uint sessionId, out IntPtr phToken);
+
+    [DllImport("userenv.dll", SetLastError = true, CharSet = CharSet.Unicode)]
+    private static extern bool GetUserProfileDirectory(IntPtr hToken, StringBuilder lpProfileDir, ref int lpcchSize, out int lpDwFlags);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    private static extern bool CloseHandle(IntPtr hObject);
+}

Services/Logging/LogMasking.cs

@@ -0,0 +1,29 @@
+namespace UtopiaCanteenSystem.Services.Logging;
+
+public static class LogMasking
+{
+    public static string MaskCardId(string? cardId)
+    {
+        if (string.IsNullOrWhiteSpace(cardId))
+            return "(empty)";
+
+        var s = cardId.Trim();
+        if (s.Length <= 4)
+            return new string('*', s.Length);
+
+        var visible = Math.Min(4, s.Length);
+        return s[..visible] + new string('*', s.Length - visible);
+    }
+
+    public static string MaskConnectionString(string? connectionString)
+    {
+        if (string.IsNullOrWhiteSpace(connectionString))
+            return "(not configured)";
+
+        var s = connectionString.Trim();
+        if (s.Length <= 20)
+            return "***";
+
+        return s[..12] + "***" + s[^4..];
+    }
+}

Services/Logging/LogPaths.cs

@@ -0,0 +1,65 @@
+using System.IO;
+
+namespace UtopiaCanteenSystem.Services.Logging;
+
+/// <summary>
+/// File log directories. Client uses the current user's LocalAppData.
+/// Backend (Windows Service) uses the interactive user's LocalAppData when possible
+/// so logs appear under the logged-on user's profile instead of systemprofile.
+/// </summary>
+public static class LogPaths
+{
+    private static string? _backendLogsDirectoryOverride;
+    private static string? _cachedLocalAppDataRoot;
+
+    /// <summary>
+    /// Optional absolute path (e.g. from appsettings LogsDirectory). Used by the backend service only.
+    /// </summary>
+    public static void SetBackendLogsDirectory(string? directory)
+    {
+        _backendLogsDirectoryOverride = string.IsNullOrWhiteSpace(directory)
+            ? null
+            : directory.Trim();
+    }
+
+    /// <summary>
+    /// Client logs folder: %LocalAppData%\UtopiaCanteenClient\Logs.
+    /// </summary>
+    public static string ClientLogsDirectory =>
+        Path.Combine(ResolveLocalAppDataRoot(), "UtopiaCanteenClient", "Logs");
+
+    /// <summary>
+    /// Backend logs folder: %LocalAppData%\UtopiaCanteenBackend\Logs
+    /// (interactive user when running as a service).
+    /// </summary>
+    public static string BackendLogsDirectory =>
+        _backendLogsDirectoryOverride ?? Path.Combine(ResolveLocalAppDataRoot(), "UtopiaCanteenBackend", "Logs");
+
+    public static string GetBackendLogFilePath(DateTime? date = null)
+    {
+        var d = date ?? DateTime.Now;
+        return Path.Combine(BackendLogsDirectory, $"backend-{d:yyyy-MM-dd}.log");
+    }
+
+    public static string GetClientLogFilePath(DateTime? date = null)
+    {
+        var d = date ?? DateTime.Now;
+        return Path.Combine(ClientLogsDirectory, $"client-{d:yyyy-MM-dd}.log");
+    }
+
+    /// <summary>
+    /// User's LocalAppData, or SYSTEM profile when no interactive session (service at login screen).
+    /// </summary>
+    public static string ResolveLocalAppDataRoot()
+    {
+        if (!string.IsNullOrEmpty(_cachedLocalAppDataRoot))
+            return _cachedLocalAppDataRoot;
+
+        var interactive = InteractiveUserPath.TryGetLocalAppDataPath();
+        if (!string.IsNullOrWhiteSpace(interactive))
+            return _cachedLocalAppDataRoot = interactive;
+
+        return _cachedLocalAppDataRoot =
+            Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+    }
+}

Services/MealMenuCacheSyncService.cs

@@ -0,0 +1,452 @@
+using Microsoft.EntityFrameworkCore;
+using MySqlConnector;
+using UtopiaCanteenSystem.Data;
+using UtopiaCanteenSystem.Models;
+using UtopiaCanteenSystem.Services.Logging;
+
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Pulls meal_schedule, lunch_menu_week, lunch_menu_item, and menu_item from HRMS into SQLite.
+/// </summary>
+public class MealMenuCacheSyncService : IMealMenuCacheSyncService
+{
+    private readonly IDbContextFactory<AppDbContext> _dbFactory;
+    private readonly IConfigService _configService;
+
+    public MealMenuCacheSyncService(IDbContextFactory<AppDbContext> dbFactory, IConfigService configService)
+    {
+        _dbFactory = dbFactory;
+        _configService = configService;
+    }
+
+    public async Task<MealMenuCacheSyncResult> SyncAllAsync(CancellationToken cancellationToken = default)
+    {
+        FileLogger.Info("CacheSync", "Meal/menu cache sync started.");
+
+        var connectionString = _configService.GetHrmsLookupConnectionString();
+        if (string.IsNullOrWhiteSpace(connectionString))
+        {
+            FileLogger.Warn("CacheSync", "Meal/menu sync skipped. MySQL connection string is not configured.");
+            return new MealMenuCacheSyncResult
+            {
+                Success = false,
+                ErrorMessage = "MySQL connection string is not configured."
+            };
+        }
+
+        try
+        {
+            var syncedAt = DateTime.UtcNow;
+            await using var db = await _dbFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
+
+            var menuItems = await FetchMenuItemsAsync(connectionString, cancellationToken).ConfigureAwait(false);
+            var mealSchedules = await FetchMealSchedulesAsync(connectionString, cancellationToken).ConfigureAwait(false);
+            var lunchWeeks = await FetchLunchMenuWeeksAsync(connectionString, cancellationToken).ConfigureAwait(false);
+            var lunchItems = await FetchLunchMenuItemsAsync(connectionString, cancellationToken).ConfigureAwait(false);
+
+            var menuItemCount = await UpsertMenuItemsAsync(db, menuItems, syncedAt, cancellationToken).ConfigureAwait(false);
+            var mealScheduleCount = await UpsertMealSchedulesAsync(db, mealSchedules, syncedAt, cancellationToken).ConfigureAwait(false);
+            var lunchWeekCount = await UpsertLunchMenuWeeksAsync(db, lunchWeeks, syncedAt, cancellationToken).ConfigureAwait(false);
+            var lunchItemCount = await UpsertLunchMenuItemsAsync(db, lunchItems, syncedAt, cancellationToken).ConfigureAwait(false);
+
+            await db.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
+            _configService.SetLastMealMenuCacheSyncUtc(syncedAt);
+
+            FileLogger.Info(
+                "CacheSync",
+                $"Meal/menu sync completed. MealSchedules={mealScheduleCount}, MenuWeeks={lunchWeekCount}, " +
+                $"MenuItems={lunchItemCount}, CatalogItems={menuItemCount}.");
+
+            return new MealMenuCacheSyncResult
+            {
+                Success = true,
+                MealScheduleCount = mealScheduleCount,
+                LunchMenuWeekCount = lunchWeekCount,
+                LunchMenuItemCount = lunchItemCount,
+                MenuItemCount = menuItemCount
+            };
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "MealMenuCacheSyncService.SyncAllAsync");
+            FileLogger.Error("CacheSync", $"Meal/menu sync failed. Error={ex.Message}", ex);
+            return new MealMenuCacheSyncResult
+            {
+                Success = false,
+                ErrorMessage = ex.Message
+            };
+        }
+    }
+
+    private static async Task<int> UpsertMenuItemsAsync(
+        AppDbContext db,
+        List<MenuItemRow> rows,
+        DateTime syncedAt,
+        CancellationToken cancellationToken)
+    {
+        var count = 0;
+        foreach (var row in rows)
+        {
+            if (row.HrmsId <= 0)
+                continue;
+
+            var existing = await db.MenuItemCache
+                .FirstOrDefaultAsync(x => x.HrmsId == row.HrmsId, cancellationToken)
+                .ConfigureAwait(false);
+
+            if (existing == null)
+            {
+                db.MenuItemCache.Add(new MenuItemCache
+                {
+                    HrmsId = row.HrmsId,
+                    ItemName = row.ItemName,
+                    ItemType = row.ItemType,
+                    Price = row.Price,
+                    ItemFor = row.ItemFor,
+                    LocationSiteId = row.LocationSiteId,
+                    LastSyncedAtUtc = syncedAt
+                });
+            }
+            else
+            {
+                existing.ItemName = row.ItemName;
+                existing.ItemType = row.ItemType;
+                existing.Price = row.Price;
+                existing.ItemFor = row.ItemFor;
+                existing.LocationSiteId = row.LocationSiteId;
+                existing.LastSyncedAtUtc = syncedAt;
+            }
+
+            count++;
+        }
+
+        return count;
+    }
+
+    private static async Task<int> UpsertMealSchedulesAsync(
+        AppDbContext db,
+        List<MealScheduleRow> rows,
+        DateTime syncedAt,
+        CancellationToken cancellationToken)
+    {
+        var count = 0;
+        foreach (var row in rows)
+        {
+            if (row.HrmsId <= 0)
+                continue;
+
+            var existing = await db.MealScheduleCache
+                .FirstOrDefaultAsync(x => x.HrmsId == row.HrmsId, cancellationToken)
+                .ConfigureAwait(false);
+
+            if (existing == null)
+            {
+                db.MealScheduleCache.Add(new MealScheduleCache
+                {
+                    HrmsId = row.HrmsId,
+                    MealName = row.MealName,
+                    StartTime = row.StartTime,
+                    EndTime = row.EndTime,
+                    CreatedAt = row.CreatedAt,
+                    UpdatedAt = row.UpdatedAt,
+                    LocationSiteId = row.LocationSiteId,
+                    LastSyncedAtUtc = syncedAt
+                });
+            }
+            else
+            {
+                existing.MealName = row.MealName;
+                existing.StartTime = row.StartTime;
+                existing.EndTime = row.EndTime;
+                existing.CreatedAt = row.CreatedAt;
+                existing.UpdatedAt = row.UpdatedAt;
+                existing.LocationSiteId = row.LocationSiteId;
+                existing.LastSyncedAtUtc = syncedAt;
+            }
+
+            count++;
+        }
+
+        return count;
+    }
+
+    private static async Task<int> UpsertLunchMenuWeeksAsync(
+        AppDbContext db,
+        List<LunchMenuWeekRow> rows,
+        DateTime syncedAt,
+        CancellationToken cancellationToken)
+    {
+        var count = 0;
+        foreach (var row in rows)
+        {
+            if (row.HrmsId <= 0)
+                continue;
+
+            var existing = await db.LunchMenuWeekCache
+                .FirstOrDefaultAsync(x => x.HrmsId == row.HrmsId, cancellationToken)
+                .ConfigureAwait(false);
+
+            if (existing == null)
+            {
+                db.LunchMenuWeekCache.Add(new LunchMenuWeekCache
+                {
+                    HrmsId = row.HrmsId,
+                    WeekStartDate = row.WeekStartDate,
+                    WeekEndDate = row.WeekEndDate,
+                    CreatedBy = row.CreatedBy,
+                    CreatedAt = row.CreatedAt,
+                    LocationSiteId = row.LocationSiteId,
+                    LastSyncedAtUtc = syncedAt
+                });
+            }
+            else
+            {
+                existing.WeekStartDate = row.WeekStartDate;
+                existing.WeekEndDate = row.WeekEndDate;
+                existing.CreatedBy = row.CreatedBy;
+                existing.CreatedAt = row.CreatedAt;
+                existing.LocationSiteId = row.LocationSiteId;
+                existing.LastSyncedAtUtc = syncedAt;
+            }
+
+            count++;
+        }
+
+        return count;
+    }
+
+    private static async Task<int> UpsertLunchMenuItemsAsync(
+        AppDbContext db,
+        List<LunchMenuItemRow> rows,
+        DateTime syncedAt,
+        CancellationToken cancellationToken)
+    {
+        var count = 0;
+        foreach (var row in rows)
+        {
+            if (row.HrmsId <= 0)
+                continue;
+
+            var existing = await db.LunchMenuItemCache
+                .FirstOrDefaultAsync(x => x.HrmsId == row.HrmsId, cancellationToken)
+                .ConfigureAwait(false);
+
+            if (existing == null)
+            {
+                db.LunchMenuItemCache.Add(new LunchMenuItemCache
+                {
+                    HrmsId = row.HrmsId,
+                    LunchMenuWeekHrmsId = row.LunchMenuWeekHrmsId,
+                    DayOfWeek = row.DayOfWeek,
+                    MealName = row.MealName,
+                    MenuItemHrmsId = row.MenuItemHrmsId,
+                    CreatedAt = row.CreatedAt,
+                    MenuDate = row.MenuDate,
+                    LastSyncedAtUtc = syncedAt
+                });
+            }
+            else
+            {
+                existing.LunchMenuWeekHrmsId = row.LunchMenuWeekHrmsId;
+                existing.DayOfWeek = row.DayOfWeek;
+                existing.MealName = row.MealName;
+                existing.MenuItemHrmsId = row.MenuItemHrmsId;
+                existing.CreatedAt = row.CreatedAt;
+                existing.MenuDate = row.MenuDate;
+                existing.LastSyncedAtUtc = syncedAt;
+            }
+
+            count++;
+        }
+
+        return count;
+    }
+
+    private static async Task<List<MealScheduleRow>> FetchMealSchedulesAsync(string connectionString, CancellationToken cancellationToken)
+    {
+        const string sql = @"
+            SELECT id, meal_name, start_time, end_time, created_at, updated_at, location_site_id
+            FROM meal_schedule";
+
+        return await QueryRowsAsync(connectionString, sql, cancellationToken, reader => new MealScheduleRow
+        {
+            HrmsId = GetInt64(reader, 0),
+            MealName = GetString(reader, 1),
+            StartTime = GetTimeString(reader, 2),
+            EndTime = GetTimeString(reader, 3),
+            CreatedAt = GetDateTimeNullable(reader, 4),
+            UpdatedAt = GetDateTimeNullable(reader, 5),
+            LocationSiteId = GetInt(reader, 6)
+        }).ConfigureAwait(false);
+    }
+
+    private static async Task<List<LunchMenuWeekRow>> FetchLunchMenuWeeksAsync(string connectionString, CancellationToken cancellationToken)
+    {
+        const string sql = @"
+            SELECT id, week_start_date, week_end_date, created_by, created_at, location_site_id
+            FROM lunch_menu_week";
+
+        return await QueryRowsAsync(connectionString, sql, cancellationToken, reader => new LunchMenuWeekRow
+        {
+            HrmsId = GetInt64(reader, 0),
+            WeekStartDate = GetDateTimeNullable(reader, 1),
+            WeekEndDate = GetDateTimeNullable(reader, 2),
+            CreatedBy = GetString(reader, 3),
+            CreatedAt = GetDateTimeNullable(reader, 4),
+            LocationSiteId = GetInt(reader, 5)
+        }).ConfigureAwait(false);
+    }
+
+    private static async Task<List<LunchMenuItemRow>> FetchLunchMenuItemsAsync(string connectionString, CancellationToken cancellationToken)
+    {
+        const string sql = @"
+            SELECT id, lunch_menu_week_id, day_of_week, meal_name, menu_item_id, created_at, menu_date
+            FROM lunch_menu_item";
+
+        return await QueryRowsAsync(connectionString, sql, cancellationToken, reader => new LunchMenuItemRow
+        {
+            HrmsId = GetInt64(reader, 0),
+            LunchMenuWeekHrmsId = GetInt64(reader, 1),
+            DayOfWeek = GetString(reader, 2),
+            MealName = GetString(reader, 3),
+            MenuItemHrmsId = GetInt64(reader, 4),
+            CreatedAt = GetDateTimeNullable(reader, 5),
+            MenuDate = GetDateTimeNullable(reader, 6)
+        }).ConfigureAwait(false);
+    }
+
+    private static async Task<List<MenuItemRow>> FetchMenuItemsAsync(string connectionString, CancellationToken cancellationToken)
+    {
+        const string sql = @"
+            SELECT id, item_name, item_type, price, item_for, location_site_id
+            FROM menu_item";
+
+        return await QueryRowsAsync(connectionString, sql, cancellationToken, reader => new MenuItemRow
+        {
+            HrmsId = GetInt64(reader, 0),
+            ItemName = GetString(reader, 1),
+            ItemType = GetString(reader, 2),
+            Price = GetDecimal(reader, 3),
+            ItemFor = GetString(reader, 4),
+            LocationSiteId = GetInt(reader, 5)
+        }).ConfigureAwait(false);
+    }
+
+    private static async Task<List<T>> QueryRowsAsync<T>(
+        string connectionString,
+        string sql,
+        CancellationToken cancellationToken,
+        Func<MySqlDataReader, T> map)
+    {
+        var rows = new List<T>();
+        await using var conn = new MySqlConnection(connectionString);
+        await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
+        await using var cmd = new MySqlCommand(sql, conn);
+        await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
+        while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
+            rows.Add(map(reader));
+        return rows;
+    }
+
+    private static string GetString(MySqlDataReader reader, int ordinal)
+    {
+        if (reader.IsDBNull(ordinal))
+            return string.Empty;
+        return reader.GetValue(ordinal)?.ToString() ?? string.Empty;
+    }
+
+    private static int GetInt(MySqlDataReader reader, int ordinal)
+    {
+        if (reader.IsDBNull(ordinal))
+            return 0;
+        var v = reader.GetValue(ordinal);
+        if (v is int i)
+            return i;
+        if (v is long l)
+            return (int)l;
+        return int.TryParse(v?.ToString(), out var parsed) ? parsed : 0;
+    }
+
+    private static long GetInt64(MySqlDataReader reader, int ordinal)
+    {
+        if (reader.IsDBNull(ordinal))
+            return 0;
+        var v = reader.GetValue(ordinal);
+        if (v is long l)
+            return l;
+        if (v is int i)
+            return i;
+        return long.TryParse(v?.ToString(), out var parsed) ? parsed : 0;
+    }
+
+    private static decimal GetDecimal(MySqlDataReader reader, int ordinal)
+    {
+        if (reader.IsDBNull(ordinal))
+            return 0m;
+        var v = reader.GetValue(ordinal);
+        return v is decimal d ? d : Convert.ToDecimal(v);
+    }
+
+    private static DateTime? GetDateTimeNullable(MySqlDataReader reader, int ordinal)
+    {
+        if (reader.IsDBNull(ordinal))
+            return null;
+        var v = reader.GetValue(ordinal);
+        if (v is DateTime dt)
+            return dt;
+        return DateTime.TryParse(v?.ToString(), out var parsed) ? parsed : null;
+    }
+
+    private static string GetTimeString(MySqlDataReader reader, int ordinal)
+    {
+        if (reader.IsDBNull(ordinal))
+            return "00:00:00";
+        var v = reader.GetValue(ordinal);
+        if (v is TimeSpan ts)
+            return ts.ToString(@"hh\:mm\:ss");
+        return v?.ToString()?.Trim() ?? "00:00:00";
+    }
+
+    private sealed class MealScheduleRow
+    {
+        public long HrmsId { get; set; }
+        public string MealName { get; set; } = string.Empty;
+        public string StartTime { get; set; } = string.Empty;
+        public string EndTime { get; set; } = string.Empty;
+        public DateTime? CreatedAt { get; set; }
+        public DateTime? UpdatedAt { get; set; }
+        public int LocationSiteId { get; set; }
+    }
+
+    private sealed class LunchMenuWeekRow
+    {
+        public long HrmsId { get; set; }
+        public DateTime? WeekStartDate { get; set; }
+        public DateTime? WeekEndDate { get; set; }
+        public string CreatedBy { get; set; } = string.Empty;
+        public DateTime? CreatedAt { get; set; }
+        public int LocationSiteId { get; set; }
+    }
+
+    private sealed class LunchMenuItemRow
+    {
+        public long HrmsId { get; set; }
+        public long LunchMenuWeekHrmsId { get; set; }
+        public string DayOfWeek { get; set; } = string.Empty;
+        public string MealName { get; set; } = string.Empty;
+        public long MenuItemHrmsId { get; set; }
+        public DateTime? CreatedAt { get; set; }
+        public DateTime? MenuDate { get; set; }
+    }
+
+    private sealed class MenuItemRow
+    {
+        public long HrmsId { get; set; }
+        public string ItemName { get; set; } = string.Empty;
+        public string ItemType { get; set; } = string.Empty;
+        public decimal Price { get; set; }
+        public string ItemFor { get; set; } = string.Empty;
+        public int LocationSiteId { get; set; }
+    }
+}

Services/MenuLookupService.cs

@@ -1,281 +1,75 @@
-using MySqlConnector;
+using Microsoft.EntityFrameworkCore;
+using UtopiaCanteenSystem.Data;
 using UtopiaCanteenSystem.Models;
 
 namespace UtopiaCanteenSystem.Services;
 
 /// <summary>
-/// Fetches lunch menu from HRMS: lunch_menu_week (by location_site_id) → lunch_menu_item → menu_item.
+/// Fetches lunch menu from local SQLite cache (lunch_menu_week → lunch_menu_item → menu_item).
-/// Uses IConfigService.GetHrmsLookupConnectionString(). Only current week is considered.
 /// </summary>
-//public class MenuLookupService : IMenuLookupService
-//{
-//    private readonly IConfigService _configService;
-
-//    public MenuLookupService(IConfigService configService)
-//    {
-//        _configService = configService;
-//    }
-
-//    /// <inheritdoc />
-//    public async Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAsync(int siteIdNumeric, CancellationToken cancellationToken = default)
-//    {
-//        // Backwards-compatible: use today's local date.
-//        return await GetMenuItemsForSiteAndDateAsync(siteIdNumeric, DateTime.Today, cancellationToken).ConfigureAwait(false);
-//    }
-
-//    /// <inheritdoc />
-//    public async Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAndDateAsync(int siteIdNumeric, DateTime menuDateLocal, CancellationToken cancellationToken = default)
-//    {
-//        var connectionString = _configService.GetHrmsLookupConnectionString();
-//        if (string.IsNullOrWhiteSpace(connectionString))
-//            return Array.Empty<HrmsMenuItem>();
-
-//        //const string sql = @"
-//        //    SELECT DISTINCT mi.id, mi.item_name, mi.item_type, mi.price
-//        //    FROM lunch_menu_week w
-//        //    JOIN lunch_menu_item li ON li.lunch_menu_week_id = w.id
-//        //    JOIN menu_item mi ON mi.id = li.menu_item_id
-//        //    WHERE w.location_site_id = @siteId
-//        //      AND CURDATE() BETWEEN w.week_start_date AND w.week_end_date
-//        //    ORDER BY mi.item_type, mi.item_name";
-
-//        const string sql = @"
-//    SELECT
-//        mi.id,
-//        mi.item_name,
-//        mi.item_type,
-//        mi.price,
-//        li.menu_date,
-//        li.day_of_week
-//    FROM lunch_menu_week w
-//    JOIN lunch_menu_item li ON li.lunch_menu_week_id = w.id
-//    JOIN menu_item mi ON mi.id = li.menu_item_id
-//    WHERE w.location_site_id = @siteId
-//      AND @menuDate BETWEEN w.week_start_date AND w.week_end_date
-//      AND li.menu_date = @menuDate
-//    ORDER BY mi.item_name;";
-
-//        //const string sql = @"
-//        //    SELECT
-//        //        mi.id,
-//        //        mi.item_name,
-//        //        mi.item_type,
-//        //        mi.price,
-//        //        li.meal_name,
-//        //        li.menu_date,
-//        //        li.day_of_week
-//        //    FROM lunch_menu_week w
-//        //    JOIN lunch_menu_item li ON li.lunch_menu_week_id = w.id
-//        //    JOIN menu_item mi ON mi.id = li.menu_item_id
-//        //    WHERE w.location_site_id = @siteId
-//        //      AND @menuDate BETWEEN w.week_start_date AND w.week_end_date
-//        //      AND li.menu_date = @menuDate
-//        //    ORDER BY li.meal_name, mi.item_name;";
-
-//        await using var conn = new MySqlConnection(connectionString);
-//        await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
-//        await using var cmd = new MySqlCommand(sql, conn);
-//        cmd.Parameters.AddWithValue("@siteId", siteIdNumeric);
-//        cmd.Parameters.AddWithValue("@menuDate", menuDateLocal.Date);
-
-//        var list = new List<HrmsMenuItem>();
-//        await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
-//        while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
-//        {
-//            //list.Add(new HrmsMenuItem
-//            //{
-//            //    MenuItemId = reader.IsDBNull(0) ? 0 : reader.GetInt32(0),
-//            //    ItemName = GetString(reader, 1),
-//            //    ItemType = GetString(reader, 2),
-//            //    Price = GetDecimal(reader, 3)
-//            //});
-
-//            list.Add(new HrmsMenuItem
-//            {
-//                MenuItemId = reader.IsDBNull(0) ? 0 : reader.GetInt32(0),
-//                ItemName = GetString(reader, 1),
-//                ItemType = GetString(reader, 2),
-//                Price = GetDecimal(reader, 3),
-//                MenuDate = GetString(reader, 4),
-//                DayOfWeek = GetString(reader, 5),
-//                MealName = string.Empty
-//            });
-
-//            //list.Add(new HrmsMenuItem
-//            //{
-//            //    MenuItemId = reader.IsDBNull(0) ? 0 : reader.GetInt32(0),
-//            //    ItemName = GetString(reader, 1),
-//            //    ItemType = GetString(reader, 2),
-//            //    Price = GetDecimal(reader, 3),
-
-//            //    MealName = GetString(reader, 4),
-//            //    MenuDate = GetString(reader, 5),
-//            //    DayOfWeek = GetString(reader, 6),
-//            //});
-//        }
-
-//        return list;
-//    }
-
-//    private static string GetString(MySqlDataReader reader, int ordinal)
-//    {
-//        if (reader.IsDBNull(ordinal)) return string.Empty;
-//        var v = reader.GetValue(ordinal);
-//        return v?.ToString() ?? string.Empty;
-//    }
-
-//    private static decimal GetDecimal(MySqlDataReader reader, int ordinal)
-//    {
-//        if (reader.IsDBNull(ordinal)) return 0m;
-//        var v = reader.GetValue(ordinal);
-//        return v is decimal d ? d : Convert.ToDecimal(v);
-//    }
-//}
-
-
-
 public class MenuLookupService : IMenuLookupService
 {
-    private readonly IConfigService _configService;
+    private readonly IDbContextFactory<AppDbContext> _dbFactory;
 
-    public MenuLookupService(IConfigService configService)
+    public MenuLookupService(IDbContextFactory<AppDbContext> dbFactory)
     {
-        _configService = configService;
+        _dbFactory = dbFactory;
     }
 
-    // Implementing the method for fetching menu items by site
     public async Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAsync(int siteIdNumeric, CancellationToken cancellationToken = default)
     {
-        // Backwards-compatible: use today's local date.
+        return await GetMenuItemsForSiteAndDateAsync(
-        return await GetMenuItemsForSiteAndDateAsync(siteIdNumeric, DateTime.Today, "NonManagement","no-active-meal-session", cancellationToken).ConfigureAwait(false);
+            siteIdNumeric,
+            DateTime.Today,
+            "NonManagement",
+            "no-active-meal-session",
+            cancellationToken).ConfigureAwait(false);
     }
 
-    // Implementing the method for fetching menu items by site, date, and gradeType
-    //public async Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAndDateAsync(int siteIdNumeric, DateTime menuDateLocal, string gradeType, CancellationToken cancellationToken = default)
-    //{
-    //    var connectionString = _configService.GetHrmsLookupConnectionString();
-    //    if (string.IsNullOrWhiteSpace(connectionString))
-    //        return Array.Empty<HrmsMenuItem>();
-
-    //    const string sql = @"
-    //        SELECT
-    //            mi.id,
-    //            mi.item_name,
-    //            mi.item_type,
-    //            mi.price,
-    //            li.menu_date,
-    //            li.day_of_week
-    //        FROM lunch_menu_week w
-    //        JOIN lunch_menu_item li ON li.lunch_menu_week_id = w.id
-    //        JOIN menu_item mi ON mi.id = li.menu_item_id
-    //        WHERE w.location_site_id = @siteId
-    //          AND @menuDate BETWEEN w.week_start_date AND w.week_end_date
-    //          AND li.menu_date = @menuDate
-    //          AND mi.item_for = @itemFor
-    //        ORDER BY mi.item_name;";
-
-    //    var itemFor = GetItemForFromGradeType(gradeType);
-
-    //    await using var conn = new MySqlConnection(connectionString);
-    //    await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
-    //    await using var cmd = new MySqlCommand(sql, conn);
-    //    cmd.Parameters.AddWithValue("@siteId", siteIdNumeric);
-    //    cmd.Parameters.AddWithValue("@menuDate", menuDateLocal.Date);
-    //    cmd.Parameters.AddWithValue("@itemFor", itemFor);
-
-    //    var list = new List<HrmsMenuItem>();
-    //    await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
-    //    while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
-    //    {
-    //        list.Add(new HrmsMenuItem
-    //        {
-    //            MenuItemId = reader.IsDBNull(0) ? 0 : reader.GetInt32(0),
-    //            ItemName = GetString(reader, 1),
-    //            ItemType = GetString(reader, 2),
-    //            Price = GetDecimal(reader, 3),
-    //            MenuDate = GetString(reader, 4),
-    //            DayOfWeek = GetString(reader, 5),
-    //            MealName = string.Empty
-    //        });
-    //    }
-
-    //    return list;
-    //}
-
-
-
-
-
     public async Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAndDateAsync(
         int siteIdNumeric,
         DateTime menuDateLocal,
         string gradeType,
-    string mealName,  // Add mealName parameter
+        string mealName,
         CancellationToken cancellationToken = default)
     {
-        var connectionString = _configService.GetHrmsLookupConnectionString();
+        if (siteIdNumeric <= 0)
-        if (string.IsNullOrWhiteSpace(connectionString))
             return Array.Empty<HrmsMenuItem>();
 
-        // Updated SQL to include meal_name filter and select meal_name
+        await using var db = await _dbFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
-        const string sql = @"
-        SELECT
-            mi.id,
-            mi.item_name,
-            mi.item_type,
-            mi.price,
-            li.menu_date,
-            li.day_of_week,
-            li.meal_name  -- Add meal_name to SELECT
-        FROM lunch_menu_week w
-        JOIN lunch_menu_item li ON li.lunch_menu_week_id = w.id
-        JOIN menu_item mi ON mi.id = li.menu_item_id
-        WHERE w.location_site_id = @siteId
-          AND @menuDate BETWEEN w.week_start_date AND w.week_end_date
-          AND li.menu_date = @menuDate
-          AND li.meal_name = @mealName  -- Filter by meal session
-          AND mi.item_for = @itemFor
-        ORDER BY mi.item_name;";
 
+        if (!await db.MenuItemCache.AnyAsync(cancellationToken).ConfigureAwait(false))
+            return Array.Empty<HrmsMenuItem>();
+
+        var menuDate = menuDateLocal.Date;
         var itemFor = HrmsMenuItemForMapping.FromGradeType(gradeType);
+        var meal = mealName?.Trim() ?? string.Empty;
 
-        await using var conn = new MySqlConnection(connectionString);
+        var query =
-        await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
+            from w in db.LunchMenuWeekCache.AsNoTracking()
-        await using var cmd = new MySqlCommand(sql, conn);
+            join li in db.LunchMenuItemCache.AsNoTracking() on w.HrmsId equals li.LunchMenuWeekHrmsId
-        cmd.Parameters.AddWithValue("@siteId", siteIdNumeric);
+            join mi in db.MenuItemCache.AsNoTracking() on li.MenuItemHrmsId equals mi.HrmsId
-        cmd.Parameters.AddWithValue("@menuDate", menuDateLocal.Date);
+            where w.LocationSiteId == siteIdNumeric
-        cmd.Parameters.AddWithValue("@mealName", mealName);  // Add mealName parameter
+                  && w.WeekStartDate != null
-        cmd.Parameters.AddWithValue("@itemFor", itemFor);
+                  && w.WeekEndDate != null
+                  && menuDate >= w.WeekStartDate.Value.Date
+                  && menuDate <= w.WeekEndDate.Value.Date
+                  && li.MenuDate != null
+                  && li.MenuDate.Value.Date == menuDate
+                  && li.MealName == meal
+                  && mi.ItemFor == itemFor
+            orderby mi.ItemName
+            select new HrmsMenuItem
+            {
+                MenuItemId = (int)mi.HrmsId,
+                ItemName = mi.ItemName,
+                ItemType = mi.ItemType,
+                Price = mi.Price,
+                MenuDate = li.MenuDate != null ? li.MenuDate.Value.ToString("yyyy-MM-dd") : string.Empty,
+                DayOfWeek = li.DayOfWeek,
+                MealName = li.MealName
+            };
 
-        var list = new List<HrmsMenuItem>();
+        return await query.ToListAsync(cancellationToken).ConfigureAwait(false);
-        await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
-        while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
-        {
-            list.Add(new HrmsMenuItem
-            {
-                MenuItemId = reader.IsDBNull(0) ? 0 : reader.GetInt32(0),
-                ItemName = GetString(reader, 1),
-                ItemType = GetString(reader, 2),
-                Price = GetDecimal(reader, 3),
-                MenuDate = GetString(reader, 4),
-                DayOfWeek = GetString(reader, 5),
-                MealName = GetString(reader, 6)  // Map meal_name from column index 6
-            });
-        }
-
-        return list;
-    }
-    private static string GetString(MySqlDataReader reader, int ordinal)
-    {
-        if (reader.IsDBNull(ordinal)) return string.Empty;
-        var v = reader.GetValue(ordinal);
-        return v?.ToString() ?? string.Empty;
-    }
-
-    private static decimal GetDecimal(MySqlDataReader reader, int ordinal)
-    {
-        if (reader.IsDBNull(ordinal)) return 0m;
-        var v = reader.GetValue(ordinal);
-        return v is decimal d ? d : Convert.ToDecimal(v);
     }
 }

Services/NavigationService.cs

@@ -1,5 +1,7 @@
 using UtopiaCanteenSystem.ViewModels;
 
+using UtopiaCanteenSystem.Services.Logging;
+
 namespace UtopiaCanteenSystem.Services;
 
 /// <summary>
@@ -28,7 +30,7 @@ public class NavigationService : INavigationService
     private readonly Func<ScannerDashboardViewModel> _scannerVm;
     private readonly Func<MainDashboardViewModel> _dashboardVm;
     private readonly Func<AdminSettingsAuthViewModel> _adminSettingsAuthVm;
-    private readonly Func<SettingsViewModel> _settingsVm;
+    private readonly Func<object> _settingsVm;
     private readonly Func<MealSchedulesViewModel> _mealSchedulesVm;
 
     public NavigationService(
@@ -37,7 +39,7 @@ public class NavigationService : INavigationService
         Func<ScannerDashboardViewModel> scannerVm,
         Func<MainDashboardViewModel> dashboardVm,
         Func<AdminSettingsAuthViewModel> adminSettingsAuthVm,
-        Func<SettingsViewModel> settingsVm,
+        Func<object> settingsVm,
         Func<MealSchedulesViewModel> mealSchedulesVm)
     {
         _session = session;
@@ -105,6 +107,7 @@ public class NavigationService : INavigationService
             NavigateToAdminLogin();
             return;
         }
+        FileLogger.Info("ClientNav", "Meal Schedules screen opened.");
         CurrentViewModel = _mealSchedulesVm();
     }
 

Services/NoOpEmployeePhotoService.cs

@@ -0,0 +1,10 @@
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Client scanners do not call HRMS for employee photos.
+/// </summary>
+public sealed class NoOpEmployeePhotoService : IEmployeePhotoService
+{
+    public Task<byte[]?> GetPhotoBytesAsync(string parentDocumentId, CancellationToken cancellationToken = default) =>
+        Task.FromResult<byte[]?>(null);
+}

Services/NoOpMealScheduleService.cs

@@ -0,0 +1,24 @@
+using UtopiaCanteenSystem.Models;
+
+namespace UtopiaCanteenSystem.Services;
+
+/// <summary>
+/// Meal schedules are owned by the backend; clients do not query HRMS directly.
+/// </summary>
+public sealed class NoOpMealScheduleService : IMealScheduleService
+{
+    public IReadOnlyList<MealSchedule> GetActiveSchedulesForSite(string siteId) =>
+        Array.Empty<MealSchedule>();
+
+    public Task<IReadOnlyList<MealSchedule>> GetAllSchedulesAsync(CancellationToken cancellationToken = default) =>
+        Task.FromResult<IReadOnlyList<MealSchedule>>(Array.Empty<MealSchedule>());
+
+    public Task<long> CreateAsync(MealSchedule schedule, CancellationToken cancellationToken = default) =>
+        Task.FromResult(0L);
+
+    public Task UpdateAsync(MealSchedule schedule, CancellationToken cancellationToken = default) =>
+        Task.CompletedTask;
+
+    public Task DeleteAsync(long id, CancellationToken cancellationToken = default) =>
+        Task.CompletedTask;
+}

Services/OfflineCacheSyncService.cs

@@ -0,0 +1,56 @@
+using UtopiaCanteenSystem.Services.Logging;
+
+namespace UtopiaCanteenSystem.Services;
+
+public class OfflineCacheSyncService : IOfflineCacheSyncService
+{
+    private readonly IEmployeeRfidTagSyncService _employeeRfidTagSync;
+    private readonly IMealMenuCacheSyncService _mealMenuCacheSync;
+
+    public OfflineCacheSyncService(
+        IEmployeeRfidTagSyncService employeeRfidTagSync,
+        IMealMenuCacheSyncService mealMenuCacheSync)
+    {
+        _employeeRfidTagSync = employeeRfidTagSync;
+        _mealMenuCacheSync = mealMenuCacheSync;
+    }
+
+    public async Task<OfflineCacheSyncResult> SyncEmployeeAndMenuCacheAsync(CancellationToken cancellationToken = default)
+    {
+        FileLogger.Info("CacheSync", "Full offline cache sync started (employee RFID + meal/menu).");
+
+        var employeeResult = await _employeeRfidTagSync.SyncAllAsync(cancellationToken).ConfigureAwait(false);
+        if (!employeeResult.Success)
+        {
+            FileLogger.Error("CacheSync", $"Full cache sync failed at employee RFID step. Error={employeeResult.ErrorMessage}");
+            return new OfflineCacheSyncResult
+            {
+                Success = false,
+                ErrorMessage = employeeResult.ErrorMessage ?? "Employee RFID cache sync failed.",
+                EmployeeSync = employeeResult
+            };
+        }
+
+        var mealMenuResult = await _mealMenuCacheSync.SyncAllAsync(cancellationToken).ConfigureAwait(false);
+        if (!mealMenuResult.Success)
+        {
+            FileLogger.Error("CacheSync", $"Full cache sync failed at meal/menu step. Error={mealMenuResult.ErrorMessage}");
+            return new OfflineCacheSyncResult
+            {
+                Success = false,
+                ErrorMessage = mealMenuResult.ErrorMessage ?? "Meal/menu cache sync failed.",
+                EmployeeSync = employeeResult,
+                MealMenuSync = mealMenuResult
+            };
+        }
+
+        FileLogger.Info("CacheSync", "Full offline cache sync completed successfully.");
+
+        return new OfflineCacheSyncResult
+        {
+            Success = true,
+            EmployeeSync = employeeResult,
+            MealMenuSync = mealMenuResult
+        };
+    }
+}

Services/RfidService.cs

@@ -200,23 +200,46 @@ public class RfidService : IRfidService
 
 
 
+    /// <summary>Processes a scan using this kiosk's site/device/IP (from config or optional API client context).</summary>
     public ScanResult ProcessScanDetailed(string cardId)
+    {
+        var ctx = new RfidScanClientContext
+        {
+            DeviceId = _configService.GetDeviceId(),
+            SiteId = _configService.GetSiteId(),
+            IpAddress = GetLocalIpAddress()
+        };
+        return ProcessScanDetailed(cardId, ctx);
+    }
+
+    /// <summary>Central server entry: uses scanner PC site/device/IP so duplicate checks and records are per kiosk.</summary>
+    public ScanResult ProcessScanDetailed(string cardId, RfidScanClientContext clientContext)
     {
         if (string.IsNullOrWhiteSpace(cardId))
             return new ScanResult(false, "Card ID cannot be empty.", 0);
 
         cardId = cardId.Trim();
 
+        var deviceId = string.IsNullOrWhiteSpace(clientContext.DeviceId)
+            ? _configService.GetDeviceId()
+            : clientContext.DeviceId.Trim();
+        var siteForKiosk = string.IsNullOrWhiteSpace(clientContext.SiteId)
+            ? _configService.GetSiteId()
+            : clientContext.SiteId.Trim();
+        var ipAddress = string.IsNullOrWhiteSpace(clientContext.IpAddress)
+            ? GetLocalIpAddress()
+            : clientContext.IpAddress.Trim();
+
         // HRMS lookup: reject if card not registered
         var employee = _employeeLookup.GetEmployeeByRfidAsync(cardId).GetAwaiter().GetResult();
         if (employee == null)
-            return new ScanResult(false, "Card not registered in HRMS.", 0);
+            return new ScanResult(false, "Card not registered in local cache.", 0);
 
         var nowUtc = DateTime.UtcNow;
         var nowLocal = DateTime.Now;
 
         // SITE VERIFICATION: Check if employee is assigned to this site
-        var currentSiteId = _configService.GetSiteId();
+        var currentSiteId = siteForKiosk;
         var normalizedCurrentSite = NormalizeSiteId(currentSiteId);
 
         var employeeSiteId = !string.IsNullOrWhiteSpace(employee.LocationSiteId)
@@ -262,10 +285,13 @@ public class RfidService : IRfidService
             */
         }
 
-        // Continue with meal session validation
+        // Continue with meal session validation (local SQLite cache only)
         var siteIdForSession = !string.IsNullOrWhiteSpace(employee.LocationSiteId)
             ? employee.LocationSiteId.Trim()
-            : _configService.GetSiteId();
+            : siteForKiosk;
+
+        if (!_mealSessionResolver.IsOfflineMealDataAvailable())
+            return new ScanResult(false, DbMealSessionResolver.OfflineCacheMissingMessage, 0, employee);
 
         var resolvedSession = _mealSessionResolver.GetCurrentSession(nowLocal, siteIdForSession);
         if (resolvedSession == null || resolvedSession.Session == MealSession.None)
@@ -277,24 +303,29 @@ public class RfidService : IRfidService
 
         using var db = _dbFactory.CreateDbContext();
 
-        // Once-per-session-per-day rule: same card, same session, same local day is not allowed.
+        var siteId = !string.IsNullOrWhiteSpace(employee.LocationSiteId)
+            ? employee.LocationSiteId.Trim()
+            : siteForKiosk;
+        var normalizedSiteForDup = NormalizeSiteId(siteId);
+
+        // Once-per-session-per-day rule: same card, same session, same local day, same site is not allowed.
         var startOfTodayLocal = DateTime.Today;
         var startOfTomorrowLocal = startOfTodayLocal.AddDays(1);
         var startUtc = startOfTodayLocal.ToUniversalTime();
         var endUtc = startOfTomorrowLocal.ToUniversalTime();
 
-        var alreadyScannedThisSessionToday = db.LunchOrderTransactions
+        var dupCandidates = db.LunchOrderTransactions
             .Where(r => r.CardId == cardId)
             .Where(r => r.MealSessionCode == sessionCode)
             .Where(r => r.ScanTime >= startUtc && r.ScanTime < endUtc)
             .OrderByDescending(r => r.ScanTime)
-            .FirstOrDefault();
+            .ToList();
+
+        var alreadyScannedThisSessionToday = dupCandidates.FirstOrDefault(r =>
+            string.Equals(NormalizeSiteId(r.SiteId), normalizedSiteForDup, StringComparison.OrdinalIgnoreCase));
 
         if (alreadyScannedThisSessionToday != null)
-        {
+            return new ScanResult(false, "Meal already taken.", 0, employee, session);
-            var sessionName = resolvedSession.MealName;
-            return new ScanResult(false, $"This card is already scanned for {sessionName} today.", 0, employee, session);
-        }
 
         var interval = _configService.GetScanInterval();
         var timeoutSeconds = (int)Math.Max(1, interval.TotalSeconds);
@@ -302,11 +333,14 @@ public class RfidService : IRfidService
         var windowStart = nowUtc.AddSeconds(-timeoutSeconds);
 
         // Safety debounce: short cooldown per card to prevent accidental double-tap.
-        var lastInWindow = db.LunchOrderTransactions
+        var windowCandidates = db.LunchOrderTransactions
             .Where(r => r.CardId == cardId)
             .Where(r => r.ScanTime >= windowStart)
             .OrderByDescending(r => r.ScanTime)
-            .FirstOrDefault();
+            .ToList();
+
+        var lastInWindow = windowCandidates.FirstOrDefault(r =>
+            string.Equals(NormalizeSiteId(r.SiteId), normalizedSiteForDup, StringComparison.OrdinalIgnoreCase));
 
         if (lastInWindow != null)
         {
@@ -319,19 +353,7 @@ public class RfidService : IRfidService
                 session);
         }
 
-        // Production duplicate check by employee serial + date + meal + site.
-        // Different meal on same day is allowed.
-        if (int.TryParse(new string(siteIdForSession.Where(char.IsDigit).ToArray()), out var siteNumericForDup) &&
-            siteNumericForDup > 0 &&
-            HasProductionMealAlreadyTaken(employee.EmployeeId, siteNumericForDup, mealLabel, nowLocal.Date))
-        {
-            return new ScanResult(false, "Meal already taken", 0, employee, session);
-        }
-
         var fullName = string.Join(" ", new[] { employee.FirstName, employee.MiddleName }.Where(s => !string.IsNullOrWhiteSpace(s))).Trim();
-        var siteId = !string.IsNullOrWhiteSpace(employee.LocationSiteId)
-            ? employee.LocationSiteId.Trim()
-            : _configService.GetSiteId();
 
         // Resolve menu items for this scan
         var mealItemsDisplay = string.Empty;
@@ -346,38 +368,10 @@ public class RfidService : IRfidService
                     .GetAwaiter()
                     .GetResult();
 
-                var authorized = menuItems
+                var matching = menuItems
                     .Where(i => i.MenuItemId > 0)
-                    .Where(i =>
-                    {
-                        try
-                        {
-                            return _employeeLookup
-                                .IsMenuItemAuthorizedForRfidAsync(cardId, i.MenuItemId)
-                                .GetAwaiter()
-                                .GetResult();
-                        }
-                        catch (Exception ex)
-                        {
-                            Logger.Log(ex, $"RfidService.EmployeeMenuValidation card={cardId}, menuItemId={i.MenuItemId}");
-                            return false;
-                        }
-                    })
                     .ToList();
 
-                // Fallback: if employee_menu_item_tag has no matches for this employee/session,
-                // still allow showing the menu items fetched from HRMS menu_item.
-                var matching = authorized.Count > 0
-                    ? authorized
-                    : menuItems.ToList();
-
-                if (authorized.Count == 0)
-                {
-                    Logger.Log(
-                        new Exception($"No employee_menu_item_tag match; using fallback menu. card={cardId}, site={siteNumeric}, date={nowLocal:yyyy-MM-dd}, meal={mealLabel}, grade={employee.GradeType}"),
-                        "RfidService.ProcessScanDetailed authorization");
-                }
-
                 var names = matching
                     .Select(i => i.ItemName)
                     .Where(n => !string.IsNullOrWhiteSpace(n))
@@ -402,8 +396,8 @@ public class RfidService : IRfidService
             ScanTime = nowUtc,
             IsSynced = false,
             SiteId = siteId,
-            DeviceId = _configService.GetDeviceId(),
+            DeviceId = deviceId,
-            IpAddress = GetLocalIpAddress(),
+            IpAddress = ipAddress,
             MealSessionCode = sessionCode,
             ParentDocumentId = employee.ParentDocumentId ?? string.Empty,
             EmployeeId = employee.EmployeeId ?? string.Empty,
@@ -425,17 +419,17 @@ public class RfidService : IRfidService
 
         // If we can reach production now, try posting immediately.
         // On success (or duplicate already in production), SyncService will mark IsSynced=1.
-        if (CanReachProduction())
+        // if (CanReachProduction())
-        {
+        // {
-            try
+        //     try
-            {
+        //     {
-                _syncService.SyncNowAsync().GetAwaiter().GetResult();
+        //         _syncService.SyncNowAsync().GetAwaiter().GetResult();
-            }
+        //     }
-            catch (Exception ex)
+        //     catch (Exception ex)
-            {
+        //     {
-                Logger.Log(ex, "RfidService.ProcessScanDetailed immediate sync");
+        //         Logger.Log(ex, "RfidService.ProcessScanDetailed immediate sync");
-            }
+        //     }
-        }
+        // }
 
         return new ScanResult(true, "Order recorded successfully.", 0, employee, session, normalizedEmployeeSite, normalizedCurrentSite);
     }

Services/SiteIdHelper.cs

@@ -0,0 +1,30 @@
+namespace UtopiaCanteenSystem.Services;
+
+internal static class SiteIdHelper
+{
+    public static int ToInt(string? siteId)
+    {
+        var s = (siteId ?? string.Empty).Trim();
+        if (string.IsNullOrEmpty(s))
+            return 0;
+        var digits = new string(s.Where(char.IsDigit).ToArray());
+        return int.TryParse(digits, out var n) ? n : 0;
+    }
+
+    public static string ToDisplayString(int siteIdInt)
+    {
+        if (siteIdInt <= 0)
+            return "01";
+        return siteIdInt <= 99 ? siteIdInt.ToString("D2") : siteIdInt.ToString();
+    }
+
+    public static string NormalizeSiteId(string? siteId)
+    {
+        var normalized = (siteId ?? string.Empty).Trim();
+        if (string.IsNullOrEmpty(normalized))
+            normalized = "01";
+        if (normalized.Length == 1 && char.IsDigit(normalized[0]))
+            normalized = normalized.PadLeft(2, '0');
+        return normalized;
+    }
+}

Services/SyncNowResult.cs

@@ -0,0 +1,10 @@
+namespace UtopiaCanteenSystem.Services;
+
+public sealed class SyncNowResult
+{
+    public int PendingCount { get; init; }
+    public int PostedCount { get; init; }
+    public int DuplicatesSkippedCount { get; init; }
+    public int FailedCount { get; init; }
+    public bool SkippedNoConnection { get; init; }
+}

Services/SyncService.cs

@@ -2,6 +2,7 @@ using Microsoft.EntityFrameworkCore;
 using MySqlConnector;
 using UtopiaCanteenSystem.Data;
 using UtopiaCanteenSystem.Models;
+using UtopiaCanteenSystem.Services.Logging;
 
 namespace UtopiaCanteenSystem.Services;
 
@@ -20,21 +21,16 @@ public class SyncService : ISyncService
         _configService = configService;
     }
 
-    public async Task SyncNowAsync(CancellationToken cancellationToken = default)
+    public async Task<SyncNowResult> SyncNowAsync(CancellationToken cancellationToken = default)
     { 
         var productionConnStr = _configService.GetMySqlConnectionString();
         if (string.IsNullOrWhiteSpace(productionConnStr))
         {
-            System.Diagnostics.Debug.WriteLine("MySQL connection string (production) not configured; skipping sync.");
+            FileLogger.Warn("OrderSync", "MySQL connection string is not configured; skipping order sync.");
-            return;
+            return new SyncNowResult { SkippedNoConnection = true };
         }
 
         var hrmsConnStr = _configService.GetHrmsLookupConnectionString();
-        if (string.IsNullOrWhiteSpace(hrmsConnStr))
-        {
-            System.Diagnostics.Debug.WriteLine("HRMS lookup connection string not configured; skipping sync (need both for lunch_order).");
-            return;
-        }
 
         List<ScanRecord> toSync;
         using (var db = _dbFactory.CreateDbContext())
@@ -46,11 +42,20 @@ public class SyncService : ISyncService
                 .ConfigureAwait(false);
         }
 
+        FileLogger.Info("OrderSync", $"Order sync started. PendingCount={toSync.Count}");
+
+        var posted = 0;
+        var duplicatesSkipped = 0;
+        var failed = 0;
+
         // Always run day-end cleanup (remove synced rows from previous days), even when there's nothing to sync.
         await CleanupOldSyncedRowsAsync(cancellationToken).ConfigureAwait(false);
 
         if (toSync.Count == 0)
-            return;
+        {
+            FileLogger.Info("OrderSync", "Order sync completed. No pending orders.");
+            return new SyncNowResult();
+        }
 
         // Production: lunch_order_transactions (GetMySqlConnectionString)
         const string insertTxnSql = @"
@@ -59,7 +64,7 @@ public class SyncService : ISyncService
             VALUES 
                 (@ScanTimeUtc, @SiteId, @DeviceId, @CardId, @IpAddress, UTC_TIMESTAMP(3))";
 
-        // HRMS/local: lunch_order (GetHrmsLookupConnectionString)
+        // HRMS/UIND: lunch_order (HrmsLookup when set, else MySqlConnectionString)
         const string existsOrderSql = @"
             SELECT id
             FROM lunch_order
@@ -140,6 +145,7 @@ public class SyncService : ISyncService
                 if (await IsDuplicateMealInProductionAsync(record, hrmsConnStr, cancellationToken).ConfigureAwait(false))
                 {
                     syncedIds.Add(record.Id);
+                    duplicatesSkipped++;
                     continue;
                 }
 
@@ -279,11 +285,12 @@ public class SyncService : ISyncService
                 }
 
                 syncedIds.Add(record.Id);
+                posted++;
             }
             catch (Exception ex)
             {
-                System.Diagnostics.Debug.WriteLine($"Sync record failed (SQLite Id={record.Id}): {ex.Message}");
+                failed++;
-                // Leave unsynced; will retry later.
+                FileLogger.Error("OrderSync", $"UIND/HRMS post failed for SQLite Id={record.Id}, CardId={LogMasking.MaskCardId(record.CardId)}.", ex);
             }
         }
 
@@ -305,8 +312,21 @@ public class SyncService : ISyncService
         }
         catch (Exception ex)
         {
-            System.Diagnostics.Debug.WriteLine($"Sync cleanup failed: {ex.Message}");
+            FileLogger.Warn("OrderSync", "Sync cleanup failed.", ex);
         }
+
+        var result = new SyncNowResult
+        {
+            PendingCount = toSync.Count,
+            PostedCount = posted,
+            DuplicatesSkippedCount = duplicatesSkipped,
+            FailedCount = failed
+        };
+        FileLogger.Info(
+            "OrderSync",
+            $"Order sync completed. Pending={result.PendingCount}, Posted={result.PostedCount}, " +
+            $"DuplicatesSkipped={result.DuplicatesSkippedCount}, Failed={result.FailedCount}.");
+        return result;
     }
 
     private static string GenerateLunchOrderCode(long id, DateTime date)

UtopiaCanteen.Backend/UtopiaCanteen.Backend.csproj

@@ -0,0 +1,49 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <RootNamespace>UtopiaCanteenSystem</RootNamespace>
+    <AssemblyName>UtopiaCanteen.Backend</AssemblyName>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\UtopiaCanteen.Shared\UtopiaCanteen.Shared.csproj" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.11" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="8.0.11" />
+    <PackageReference Include="MySqlConnector" Version="2.3.5" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="8.0.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="..\Data\**\*.cs" LinkBase="Data" />
+    <Compile Include="..\Models\**\*.cs" LinkBase="Models" />
+    <Compile Include="..\Helpers\**\*.cs" LinkBase="Helpers" />
+    <Compile Include="..\Api\CanteenBackendHost.cs" Link="Api\CanteenBackendHost.cs" />
+    <Compile Include="..\Api\ApiDtoMapper.cs" Link="Api\ApiDtoMapper.cs" />
+    <Compile Include="..\Services\**\*.cs" LinkBase="Services" />
+    <Compile Remove="..\Services\CanteenBackendApiClient.cs" />
+    <Compile Remove="..\Services\ICanteenBackendApiClient.cs" />
+    <Compile Remove="..\Services\EmptyMenuLookupService.cs" />
+    <Compile Remove="..\Services\AuthService.cs" />
+    <Compile Remove="..\Services\IAuthService.cs" />
+    <Compile Remove="..\Services\AuthResult.cs" />
+    <Compile Remove="..\Services\NavigationService.cs" />
+    <Compile Remove="..\Services\INavigationService.cs" />
+    <Compile Remove="..\Services\AppSession.cs" />
+    <Compile Remove="..\Services\AdminAuditService.cs" />
+    <Compile Remove="..\Services\IAdminAuditService.cs" />
+    <Compile Remove="..\Services\EmployeePhotoService.cs" />
+    <Compile Remove="..\Services\IEmployeePhotoService.cs" />
+    <Compile Remove="..\Services\SampleSyncApiController.cs" />
+    <Compile Remove="..\Services\ClientConfigService.cs" />
+    <Compile Remove="..\Services\NoOpEmployeePhotoService.cs" />
+    <Compile Remove="..\Services\NoOpMealScheduleService.cs" />
+    <Compile Remove="..\Models\OrderHistoryItem.cs" />
+    <Compile Remove="..\Services\ConfigService.cs" />
+    <Compile Remove="..\Services\BackendApiMealScheduleService.cs" />
+    <Compile Remove="..\Services\AdminLoginHelper.cs" />
+    <Compile Remove="..\Api\RfidApiDtos.cs" />
+    <Compile Remove="..\Api\BackendApiDtos.cs" />
+  </ItemGroup>
+</Project>

UtopiaCanteen.BackendService/BackendHostConfigService.cs

@@ -0,0 +1,211 @@
+using System.Text.Json;
+using Microsoft.Extensions.Configuration;
+using UtopiaCanteenSystem.Data;
+using UtopiaCanteenSystem.Models;
+using UtopiaCanteenSystem.Services;
+
+namespace UtopiaCanteen.BackendService;
+
+/// <summary>
+/// Backend service configuration: appsettings.json + persisted JSON under LocalApplicationData.
+/// </summary>
+public sealed class BackendHostConfigService : IConfigService
+{
+    private readonly IConfiguration _configuration;
+    private readonly string _persistedPath;
+    private PersistedConfig _persisted;
+
+    public BackendHostConfigService(IConfiguration configuration)
+    {
+        _configuration = configuration;
+        _persistedPath = Path.Combine(DatabasePath.GetAppDataFolder(), "backend-settings.json");
+        _persisted = LoadPersisted();
+        MergeFromAppSettingsIfNeeded();
+    }
+
+    public string GetListenUrls() =>
+        _configuration["ListenUrls"] ?? "http://0.0.0.0:5000";
+
+    public string GetSyncApiEndpoint() => _configuration["SyncApiEndpoint"] ?? _persisted.SyncApiEndpoint ?? string.Empty;
+    public void SetSyncApiEndpoint(string endpoint) { _persisted.SyncApiEndpoint = endpoint ?? string.Empty; SavePersisted(); }
+
+    public bool GetSyncServiceEnabled() =>
+        _configuration.GetValue("SyncServiceEnabled", _persisted.SyncServiceEnabled);
+
+    public void SetSyncServiceEnabled(bool enabled) { _persisted.SyncServiceEnabled = enabled; SavePersisted(); }
+
+    public bool GetScannerConnected() => false;
+    public void SetScannerConnected(bool connected) { }
+
+    public int GetScanIntervalDays() => 0;
+    public void SetScanIntervalDays(int value) { }
+    public int GetScanIntervalHours() => 0;
+    public void SetScanIntervalHours(int value) { }
+    public int GetScanIntervalMinutes() => 1;
+    public void SetScanIntervalMinutes(int value) { }
+    public int GetScanIntervalSeconds() => 0;
+    public void SetScanIntervalSeconds(int value) { }
+    public TimeSpan GetScanInterval() => TimeSpan.FromMinutes(1);
+
+    public string GetAdminCardId() => "ADMIN";
+    public void SetAdminCardId(string cardId) { }
+
+    public string GetSiteId() => _persisted.SiteId ?? "02";
+    public void SetSiteId(string siteId) { _persisted.SiteId = siteId ?? string.Empty; SavePersisted(); }
+
+    public void ApplyLocationSiteIdFromAuth(string? locationSiteId) { }
+
+    public string GetDeviceId()
+    {
+        if (!string.IsNullOrWhiteSpace(_persisted.DeviceId))
+            return _persisted.DeviceId.Trim();
+
+        _persisted.DeviceId = ResolveMachineDeviceId();
+        SavePersisted();
+        return _persisted.DeviceId;
+    }
+
+    public void SetDeviceId(string deviceId)
+    {
+        _persisted.DeviceId = string.IsNullOrWhiteSpace(deviceId)
+            ? ResolveMachineDeviceId()
+            : deviceId.Trim();
+        SavePersisted();
+    }
+
+    public bool GetRememberAdminCredentials() => false;
+    public void SetRememberAdminCredentials(bool remember) { }
+    public string GetSavedAdminUsername() => string.Empty;
+    public void SetSavedAdminUsername(string username) { }
+    public string GetSavedAdminPassword() => string.Empty;
+    public void SetSavedAdminPassword(string password) { }
+
+    public string GetMySqlConnectionString() =>
+        FirstNonEmpty(_configuration["MySqlConnectionString"], _persisted.MySqlConnectionString);
+
+    public void SetMySqlConnectionString(string connectionString)
+    {
+        _persisted.MySqlConnectionString = connectionString ?? string.Empty;
+        SavePersisted();
+    }
+
+    public string GetHrmsLookupConnectionString() =>
+        ConfigConnectionHelper.GetHrmsOrProductionConnectionString(
+            FirstNonEmpty(_configuration["HrmsLookupConnectionString"], _persisted.HrmsLookupConnectionString),
+            GetMySqlConnectionString());
+
+    public void SetHrmsLookupConnectionString(string connectionString)
+    {
+        _persisted.HrmsLookupConnectionString = connectionString ?? string.Empty;
+        SavePersisted();
+    }
+
+    public DateTime? GetLastEmployeeRfidCacheSyncUtc() => _persisted.LastEmployeeRfidCacheSyncUtc;
+    public void SetLastEmployeeRfidCacheSyncUtc(DateTime utc)
+    {
+        _persisted.LastEmployeeRfidCacheSyncUtc = utc;
+        SavePersisted();
+    }
+
+    public DateTime? GetLastMealMenuCacheSyncUtc() => _persisted.LastMealMenuCacheSyncUtc;
+    public void SetLastMealMenuCacheSyncUtc(DateTime utc)
+    {
+        _persisted.LastMealMenuCacheSyncUtc = utc;
+        SavePersisted();
+    }
+
+    public AppMode GetAppMode() => AppMode.Server;
+    public void SetAppMode(AppMode mode) { }
+
+    public string GetCentralServerBaseUrl() => string.Empty;
+    public void SetCentralServerBaseUrl(string url) { }
+
+    public string GetBackendBaseUrl() => DeriveLocalhostApiBaseUrl(GetListenUrls());
+
+    public string GetLocalServerListenUrls() => GetListenUrls();
+    public void SetLocalServerListenUrls(string urls) { }
+
+    private static string ResolveMachineDeviceId()
+    {
+        var machineName = Environment.MachineName;
+        return string.IsNullOrWhiteSpace(machineName)
+            ? Guid.NewGuid().ToString("N")
+            : machineName.Trim();
+    }
+
+    private void MergeFromAppSettingsIfNeeded()
+    {
+        var mysql = _configuration["MySqlConnectionString"];
+        if (!string.IsNullOrWhiteSpace(mysql) && string.IsNullOrWhiteSpace(_persisted.MySqlConnectionString))
+            _persisted.MySqlConnectionString = mysql;
+
+        var hrms = _configuration["HrmsLookupConnectionString"];
+        if (!string.IsNullOrWhiteSpace(hrms) && string.IsNullOrWhiteSpace(_persisted.HrmsLookupConnectionString))
+            _persisted.HrmsLookupConnectionString = hrms;
+
+        SavePersisted();
+    }
+
+    private static string FirstNonEmpty(params string?[] values)
+    {
+        foreach (var v in values)
+        {
+            if (!string.IsNullOrWhiteSpace(v))
+                return v!;
+        }
+        return string.Empty;
+    }
+
+    private static string DeriveLocalhostApiBaseUrl(string listenUrls)
+    {
+        var first = listenUrls
+            .Split(new[] { ';', ',' }, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
+            .FirstOrDefault() ?? "http://0.0.0.0:5000";
+        first = first.TrimEnd('/');
+        if (first.Contains("0.0.0.0", StringComparison.Ordinal))
+            first = first.Replace("0.0.0.0", "localhost", StringComparison.Ordinal);
+        if (first.Contains('+'))
+            first = first.Replace("+", "localhost", StringComparison.Ordinal);
+        return first;
+    }
+
+    private PersistedConfig LoadPersisted()
+    {
+        try
+        {
+            if (!File.Exists(_persistedPath))
+                return new PersistedConfig();
+            var json = File.ReadAllText(_persistedPath);
+            return JsonSerializer.Deserialize<PersistedConfig>(json) ?? new PersistedConfig();
+        }
+        catch
+        {
+            return new PersistedConfig();
+        }
+    }
+
+    private void SavePersisted()
+    {
+        try
+        {
+            var json = JsonSerializer.Serialize(_persisted, new JsonSerializerOptions { WriteIndented = true });
+            File.WriteAllText(_persistedPath, json);
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "BackendHostConfigService.SavePersisted");
+        }
+    }
+
+    private sealed class PersistedConfig
+    {
+        public string? SyncApiEndpoint { get; set; }
+        public bool SyncServiceEnabled { get; set; } = true;
+        public string? MySqlConnectionString { get; set; }
+        public string? HrmsLookupConnectionString { get; set; }
+        public DateTime? LastEmployeeRfidCacheSyncUtc { get; set; }
+        public DateTime? LastMealMenuCacheSyncUtc { get; set; }
+        public string? SiteId { get; set; }
+        public string? DeviceId { get; set; }
+    }
+}

UtopiaCanteen.BackendService/CanteenBackendWorker.cs

@@ -0,0 +1,254 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using UtopiaCanteenSystem.Api;
+using UtopiaCanteenSystem.Data;
+using UtopiaCanteenSystem.Services;
+using UtopiaCanteenSystem.Services.Logging;
+
+namespace UtopiaCanteen.BackendService;
+
+public sealed class CanteenBackendWorker : BackgroundService
+{
+    private readonly IConfigService _config;
+    private readonly DbContextFactory _dbFactory;
+    private readonly IConfiguration _configuration;
+    private readonly ILogger<CanteenBackendWorker> _logger;
+    private CancellationTokenSource? _apiCts;
+    private Task? _apiTask;
+    private System.Timers.Timer? _cacheSyncTimer;
+    private System.Timers.Timer? _orderSyncTimer;
+    private int _cacheSyncRunning;
+    private int _orderSyncRunning;
+    private CanteenBackendServices? _backend;
+
+    public CanteenBackendWorker(
+        IConfigService config,
+        DbContextFactory dbFactory,
+        IConfiguration configuration,
+        ILogger<CanteenBackendWorker> logger)
+    {
+        _config = config;
+        _dbFactory = dbFactory;
+        _configuration = configuration;
+        _logger = logger;
+    }
+
+    public override async Task StartAsync(CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("Service starting...");
+        FileLogger.Info("BackendService", "Service starting...");
+
+        try
+        {
+            using (var db = _dbFactory.CreateDbContext())
+                db.EnsureDatabaseCreated();
+
+            FileLogger.Info("BackendService", $"Configuration loaded. SQLite DB path={DatabasePath.GetDbPath()}");
+            FileLogger.Info(
+                "BackendService",
+                $"Device ID resolved. MachineName={Environment.MachineName}, DeviceId={_config.GetDeviceId()}");
+            FileLogger.Info("BackendService", $"ListenUrls={_config.GetLocalServerListenUrls()}");
+            FileLogger.Info(
+                "BackendService",
+                $"MySqlConnectionString={LogMasking.MaskConnectionString(_config.GetMySqlConnectionString())}");
+            FileLogger.Info(
+                "BackendService",
+                $"HrmsConnection(effective)={LogMasking.MaskConnectionString(_config.GetHrmsLookupConnectionString())}");
+            FileLogger.Info("BackendService", $"Logs directory={LogPaths.BackendLogsDirectory}");
+        }
+        catch (Exception ex)
+        {
+            FileLogger.Error("BackendService", "Failed during startup initialization.", ex);
+            throw;
+        }
+
+        var employeeRfidTagSync = new EmployeeRfidTagSyncService(_dbFactory, _config);
+        var mealMenuCacheSync = new MealMenuCacheSyncService(_dbFactory, _config);
+        var offlineCacheSync = new OfflineCacheSyncService(employeeRfidTagSync, mealMenuCacheSync);
+        var employeeLookup = new EmployeeLookupService(_dbFactory, _config);
+        var menuLookup = new MenuLookupService(_dbFactory);
+        var mealSessionResolver = new DbMealSessionResolver(_dbFactory);
+        var productionSync = new SyncService(_dbFactory, _config);
+        var rfid = new RfidService(_dbFactory, _config, employeeLookup, mealSessionResolver, menuLookup, productionSync);
+        _backend = new CanteenBackendServices(rfid, offlineCacheSync, productionSync, _config);
+
+        _apiCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+        var listenUrls = _config.GetLocalServerListenUrls();
+        var backend = _backend;
+        var cts = _apiCts;
+        _apiTask = Task.Run(async () =>
+        {
+            try
+            {
+                await Task.Delay(500, cts.Token).ConfigureAwait(false);
+                await CanteenBackendHost.RunAsync(backend, listenUrls, cts.Token).ConfigureAwait(false);
+            }
+            catch (OperationCanceledException)
+            {
+                FileLogger.Info("BackendService", "API host stopped (cancellation).");
+            }
+            catch (Exception ex)
+            {
+                FileLogger.Error("BackendService", "API host failed.", ex);
+                Logger.Log(ex, "CanteenBackendWorker.ApiHost");
+            }
+        }, CancellationToken.None);
+
+        _ = RunStartupCacheSyncAsync(cancellationToken);
+
+        var cacheMinutes = Math.Max(1, _configuration.GetValue("CacheSyncIntervalMinutes", 15));
+        if (!string.IsNullOrWhiteSpace(_config.GetHrmsLookupConnectionString()))
+        {
+            _cacheSyncTimer = new System.Timers.Timer(TimeSpan.FromMinutes(cacheMinutes).TotalMilliseconds) { AutoReset = true };
+            _cacheSyncTimer.Elapsed += async (_, _) => await RunCacheSyncSafeAsync("timer").ConfigureAwait(false);
+            _cacheSyncTimer.Start();
+            FileLogger.Info("BackendService", $"Background cache sync timer started. IntervalMinutes={cacheMinutes}");
+        }
+        else
+        {
+            FileLogger.Warn("BackendService", "Background cache sync timer not started (MySQL/HRMS connection not configured).");
+        }
+
+        var orderMinutes = Math.Max(1, _configuration.GetValue("ProductionSyncIntervalMinutes", 1));
+        if (_config.GetSyncServiceEnabled() && !string.IsNullOrWhiteSpace(_config.GetMySqlConnectionString()))
+        {
+            _orderSyncTimer = new System.Timers.Timer(TimeSpan.FromMinutes(orderMinutes).TotalMilliseconds) { AutoReset = true };
+            _orderSyncTimer.Elapsed += async (_, _) => await RunOrderSyncSafeAsync("timer").ConfigureAwait(false);
+            _orderSyncTimer.Start();
+            FileLogger.Info("BackendService", $"Background production sync timer started. IntervalMinutes={orderMinutes}");
+        }
+        else
+        {
+            FileLogger.Warn("BackendService", "Background production sync timer not started (disabled or MySQL not configured).");
+        }
+
+        _logger.LogInformation("Service started.");
+        FileLogger.Info("BackendService", "Service started.");
+        await base.StartAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    public override async Task StopAsync(CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("Service stopping...");
+        FileLogger.Info("BackendService", "Service stopping...");
+        _cacheSyncTimer?.Stop();
+        _orderSyncTimer?.Stop();
+        _apiCts?.Cancel();
+        if (_apiTask != null)
+        {
+            try
+            {
+                await _apiTask.WaitAsync(TimeSpan.FromSeconds(10), cancellationToken).ConfigureAwait(false);
+            }
+            catch
+            {
+                // Best-effort
+            }
+        }
+
+        _cacheSyncTimer?.Dispose();
+        _orderSyncTimer?.Dispose();
+        _apiCts?.Dispose();
+        FileLogger.Info("BackendService", "Service stopped.");
+        await base.StopAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    protected override Task ExecuteAsync(CancellationToken stoppingToken) =>
+        Task.Delay(Timeout.Infinite, stoppingToken);
+
+    private async Task RunStartupCacheSyncAsync(CancellationToken cancellationToken)
+    {
+        if (_backend == null || string.IsNullOrWhiteSpace(_config.GetHrmsLookupConnectionString()))
+        {
+            FileLogger.Info("CacheSync", "Startup cache sync skipped (MySQL/HRMS connection not configured).");
+            return;
+        }
+
+        FileLogger.Info("CacheSync", "Startup cache sync started.");
+        for (var i = 0; i < 30 && !cancellationToken.IsCancellationRequested; i++)
+        {
+            try
+            {
+                await _backend.RunCacheSyncExclusiveAsync(async () =>
+                {
+                    await _backend.OfflineCacheSync.SyncEmployeeAndMenuCacheAsync().ConfigureAwait(false);
+                    return true;
+                }).ConfigureAwait(false);
+                FileLogger.Info("CacheSync", "Startup cache sync completed.");
+                return;
+            }
+            catch (Exception ex)
+            {
+                FileLogger.Warn("CacheSync", $"Startup cache sync attempt {i + 1} failed; retrying.", ex);
+                Logger.Log(ex, "CanteenBackendWorker.RunStartupCacheSyncAsync");
+            }
+            await Task.Delay(1000, cancellationToken).ConfigureAwait(false);
+        }
+
+        FileLogger.Error("CacheSync", "Startup cache sync failed after retries.");
+    }
+
+    private async Task RunCacheSyncSafeAsync(string trigger)
+    {
+        if (_backend == null)
+            return;
+
+        if (Interlocked.Exchange(ref _cacheSyncRunning, 1) == 1)
+        {
+            FileLogger.Info("CacheSync", $"Background cache sync skipped ({trigger}): already running.");
+            return;
+        }
+
+        FileLogger.Info("CacheSync", $"Background cache sync started ({trigger}).");
+        try
+        {
+            await _backend.RunCacheSyncExclusiveAsync(async () =>
+            {
+                await _backend.OfflineCacheSync.SyncEmployeeAndMenuCacheAsync().ConfigureAwait(false);
+                return true;
+            }).ConfigureAwait(false);
+            FileLogger.Info("CacheSync", $"Background cache sync completed ({trigger}).");
+        }
+        catch (Exception ex)
+        {
+            FileLogger.Error("CacheSync", $"Background cache sync failed ({trigger}).", ex);
+            Logger.Log(ex, "CanteenBackendWorker.RunCacheSyncSafeAsync");
+        }
+        finally
+        {
+            Interlocked.Exchange(ref _cacheSyncRunning, 0);
+        }
+    }
+
+    private async Task RunOrderSyncSafeAsync(string trigger)
+    {
+        if (_backend == null)
+            return;
+
+        if (Interlocked.Exchange(ref _orderSyncRunning, 1) == 1)
+        {
+            FileLogger.Info("OrderSync", $"Background order sync skipped ({trigger}): already running.");
+            return;
+        }
+
+        FileLogger.Info("OrderSync", $"Background order sync started ({trigger}).");
+        try
+        {
+            await _backend.RunOrderSyncExclusiveAsync(async () =>
+            {
+                await _backend.ProductionSync.SyncNowAsync().ConfigureAwait(false);
+                return true;
+            }).ConfigureAwait(false);
+            FileLogger.Info("OrderSync", $"Background order sync completed ({trigger}).");
+        }
+        catch (Exception ex)
+        {
+            FileLogger.Error("OrderSync", $"Background order sync failed ({trigger}).", ex);
+            Logger.Log(ex, "CanteenBackendWorker.RunOrderSyncSafeAsync");
+        }
+        finally
+        {
+            Interlocked.Exchange(ref _orderSyncRunning, 0);
+        }
+    }
+}

UtopiaCanteen.BackendService/Program.cs

@@ -0,0 +1,27 @@
+using Microsoft.EntityFrameworkCore;
+using UtopiaCanteen.BackendService;
+using UtopiaCanteenSystem.Data;
+using UtopiaCanteenSystem.Services;
+using UtopiaCanteenSystem.Services.Logging;
+
+DatabasePath.UseBackendServiceStorage();
+
+var builder = Host.CreateApplicationBuilder(args);
+var logsDirectory = builder.Configuration["LogsDirectory"];
+if (!string.IsNullOrWhiteSpace(logsDirectory))
+    LogPaths.SetBackendLogsDirectory(logsDirectory);
+
+FileLogger.ConfigureBackend();
+builder.Logging.ClearProviders();
+builder.Logging.AddProvider(new FileLoggerProvider());
+builder.Services.AddWindowsService(options =>
+{
+    options.ServiceName = "UtopiaCanteenBackend";
+});
+
+builder.Services.AddSingleton<IConfigService, BackendHostConfigService>();
+builder.Services.AddSingleton<DbContextFactory>();
+builder.Services.AddHostedService<CanteenBackendWorker>();
+
+var host = builder.Build();
+await host.RunAsync();

UtopiaCanteen.BackendService/UtopiaCanteen.BackendService.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk.Worker">
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <RootNamespace>UtopiaCanteen.BackendService</RootNamespace>
+    <AssemblyName>UtopiaCanteen.BackendService</AssemblyName>
+    <OutputType>Exe</OutputType>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\UtopiaCanteen.Backend\UtopiaCanteen.Backend.csproj" />
+    <PackageReference Include="Microsoft.Extensions.Hosting.WindowsServices" Version="8.0.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Update="appsettings.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+</Project>

UtopiaCanteen.Client/App.xaml

@@ -0,0 +1,31 @@
+<Application x:Class="UtopiaCanteen.Client.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:vm="clr-namespace:UtopiaCanteenSystem.ViewModels"
+             xmlns:clientVm="clr-namespace:UtopiaCanteen.Client.ViewModels"
+             xmlns:views="clr-namespace:UtopiaCanteenSystem.Views"
+             xmlns:clientViews="clr-namespace:UtopiaCanteen.Client.Views">
+    <Application.Resources>
+        <ResourceDictionary>
+            <BooleanToVisibilityConverter x:Key="BoolToVisibility" />
+            <DataTemplate DataType="{x:Type vm:AdminLoginViewModel}">
+                <views:AdminLoginView />
+            </DataTemplate>
+            <DataTemplate DataType="{x:Type vm:AdminSettingsAuthViewModel}">
+                <views:AdminSettingsAuthView />
+            </DataTemplate>
+            <DataTemplate DataType="{x:Type vm:ScannerDashboardViewModel}">
+                <views:ScannerDashboardView />
+            </DataTemplate>
+            <DataTemplate DataType="{x:Type vm:MainDashboardViewModel}">
+                <views:MainDashboardView />
+            </DataTemplate>
+            <DataTemplate DataType="{x:Type clientVm:ClientSettingsViewModel}">
+                <clientViews:ClientSettingsView />
+            </DataTemplate>
+            <DataTemplate DataType="{x:Type vm:MealSchedulesViewModel}">
+                <views:MealSchedulesView />
+            </DataTemplate>
+        </ResourceDictionary>
+    </Application.Resources>
+</Application>

UtopiaCanteen.Client/App.xaml.cs

@@ -0,0 +1,77 @@
+using System.Net.Http;
+using System.Windows;
+using Microsoft.EntityFrameworkCore;
+using UtopiaCanteenSystem;
+using UtopiaCanteenSystem.Data;
+using UtopiaCanteenSystem.Services;
+using UtopiaCanteenSystem.Services.Logging;
+using UtopiaCanteen.Client.ViewModels;
+using UtopiaCanteenSystem.ViewModels;
+
+namespace UtopiaCanteen.Client;
+
+public partial class App : Application
+{
+    private static Mutex _mutex = null!;
+
+    protected override void OnStartup(StartupEventArgs e)
+    {
+        base.OnStartup(e);
+
+        DatabasePath.UseClientStorage();
+        FileLogger.ConfigureClient();
+        FileLogger.Info("ClientApp", "Application started.");
+
+        bool isNewInstance;
+        _mutex = new Mutex(true, "UtopiaCanteenClientMutex", out isNewInstance);
+
+        if (!isNewInstance)
+        {
+            MessageBox.Show("Another instance of the scanner client is already running.", "Warning",
+                MessageBoxButton.OK, MessageBoxImage.Warning);
+            Current.Shutdown();
+            return;
+        }
+
+        var configService = new ClientConfigService();
+        FileLogger.Info("ClientApp", $"BackendBaseUrl = {configService.GetBackendBaseUrl()}");
+        FileLogger.Info(
+            "ClientApp",
+            $"Device ID resolved. MachineName={Environment.MachineName}, DeviceId={configService.GetDeviceId()}");
+        FileLogger.Info("ClientApp", $"Logs directory={LogPaths.ClientLogsDirectory}");
+
+        var httpClient = new HttpClient { Timeout = TimeSpan.FromMinutes(5) };
+        var backendApiClient = new CanteenBackendApiClient(httpClient, configService);
+
+        var dbFactory = new DbContextFactory();
+        using (var db = dbFactory.CreateDbContext())
+            db.EnsureDatabaseCreated();
+
+        var employeeLookupService = new EmployeeLookupService(dbFactory, configService);
+        var menuLookupService = new EmptyMenuLookupService();
+        var employeePhotoService = new NoOpEmployeePhotoService();
+        var adminAuditService = new AdminAuditService(dbFactory);
+        var session = new AppSession();
+        var authService = new AuthService("https://portal.utopiaindustries.pk/uind/rest/auth/user/");
+
+        NavigationService navigationService = null!;
+        navigationService = new NavigationService(
+            session,
+            () => new AdminLoginViewModel(authService, session, navigationService, configService, adminAuditService, employeeLookupService, backendApiClient),
+            () => new ScannerDashboardViewModel(backendApiClient, navigationService, session, configService, menuLookupService, employeePhotoService),
+            () => new MainDashboardViewModel(navigationService, backendApiClient, configService, session),
+            () => new AdminSettingsAuthViewModel(authService, session, navigationService, configService, employeeLookupService, backendApiClient),
+            () => new ClientSettingsViewModel(configService, navigationService, backendApiClient, session),
+            () => new MealSchedulesViewModel(new BackendApiMealScheduleService(backendApiClient), navigationService, configService));
+
+        var mainWindow = new MainWindow { DataContext = new MainViewModel(navigationService) };
+        mainWindow.WindowState = WindowState.Maximized;
+        mainWindow.Show();
+    }
+
+    protected override void OnExit(ExitEventArgs e)
+    {
+        _mutex?.ReleaseMutex();
+        base.OnExit(e);
+    }
+}

UtopiaCanteen.Client/UtopiaCanteen.Client.csproj

@@ -0,0 +1,90 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net8.0-windows</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <UseWPF>true</UseWPF>
+    <RootNamespace>UtopiaCanteen.Client</RootNamespace>
+    <AssemblyName>UtopiaCanteen.Client</AssemblyName>
+    <ApplicationIcon Condition="Exists('..\assets\favicon.ico')">..\assets\favicon.ico</ApplicationIcon>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\UtopiaCanteen.Shared\UtopiaCanteen.Shared.csproj" />
+    <PackageReference Include="CommunityToolkit.Mvvm" Version="8.2.2" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.11" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="8.0.11" />
+    <PackageReference Include="MySqlConnector" Version="2.3.5" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Page Include="..\MainWindow.xaml" Link="MainWindow.xaml">
+      <Generator>MSBuild:Compile</Generator>
+      <SubType>Designer</SubType>
+    </Page>
+    <Page Include="..\Views\**\*.xaml" LinkBase="Views" Exclude="..\Views\SettingsView.xaml">
+      <Generator>MSBuild:Compile</Generator>
+      <SubType>Designer</SubType>
+    </Page>
+    <Compile Include="..\MainWindow.xaml.cs" Link="MainWindow.xaml.cs" />
+    <Compile Include="..\Views\**\*.xaml.cs" LinkBase="Views" Exclude="..\Views\SettingsView.xaml.cs" />
+    <Compile Include="..\ViewModels\**\*.cs" LinkBase="ViewModels" Exclude="..\ViewModels\SettingsViewModel.cs" />
+    <Compile Include="..\Converters\**\*.cs" LinkBase="Converters" />
+    <Compile Include="..\Helpers\**\*.cs" LinkBase="Helpers" />
+    <Compile Include="..\Models\ScanRecord.cs" Link="Models\ScanRecord.cs" />
+    <Compile Include="..\Models\HrmsEmployeeInfo.cs" Link="Models\HrmsEmployeeInfo.cs" />
+    <Compile Include="..\Models\MealSession.cs" Link="Models\MealSession.cs" />
+    <Compile Include="..\Models\ResolvedMealSession.cs" Link="Models\ResolvedMealSession.cs" />
+    <Compile Include="..\Models\OrderHistoryItem.cs" Link="Models\OrderHistoryItem.cs" />
+    <Compile Include="..\Models\AdminLoginRecord.cs" Link="Models\AdminLoginRecord.cs" />
+    <Compile Include="..\Models\HrmsMenuItem.cs" Link="Models\HrmsMenuItem.cs" />
+    <Compile Include="..\Models\MealSchedule.cs" Link="Models\MealSchedule.cs" />
+    <Compile Include="..\Models\Labour.cs" Link="Models\Labour.cs" />
+    <Compile Include="..\Models\EmployeeRfidTagCache.cs" Link="Models\EmployeeRfidTagCache.cs" />
+    <Compile Include="..\Models\MealScheduleCache.cs" Link="Models\MealScheduleCache.cs" />
+    <Compile Include="..\Models\LunchMenuWeekCache.cs" Link="Models\LunchMenuWeekCache.cs" />
+    <Compile Include="..\Models\LunchMenuItemCache.cs" Link="Models\LunchMenuItemCache.cs" />
+    <Compile Include="..\Models\MenuItemCache.cs" Link="Models\MenuItemCache.cs" />
+    <Compile Include="..\Models\AppMode.cs" Link="Models\AppMode.cs" />
+    <Compile Include="..\Data\AppDbContext.cs" Link="Data\AppDbContext.cs" />
+    <Compile Include="..\Data\DbContextFactory.cs" Link="Data\DbContextFactory.cs" />
+    <Compile Include="..\Data\DatabasePath.cs" Link="Data\DatabasePath.cs" />
+    <Compile Include="..\Services\CanteenBackendApiClient.cs" Link="Services\CanteenBackendApiClient.cs" />
+    <Compile Include="..\Services\ICanteenBackendApiClient.cs" Link="Services\ICanteenBackendApiClient.cs" />
+    <Compile Include="..\Services\ClientConfigService.cs" Link="Services\ClientConfigService.cs" />
+    <Compile Include="..\Services\IConfigService.cs" Link="Services\IConfigService.cs" />
+    <Compile Include="..\Services\EmptyMenuLookupService.cs" Link="Services\EmptyMenuLookupService.cs" />
+    <Compile Include="..\Services\IMenuLookupService.cs" Link="Services\IMenuLookupService.cs" />
+    <Compile Include="..\Services\IRfidService.cs" Link="Services\IRfidService.cs" />
+    <Compile Include="..\Services\ScanResult.cs" Link="Services\ScanResult.cs" />
+    <Compile Include="..\Services\Logger.cs" Link="Services\Logger.cs" />
+    <Compile Include="..\Services\Logging\**\*.cs" LinkBase="Services\Logging" />
+    <Compile Include="..\Services\SyncNowResult.cs" Link="Services\SyncNowResult.cs" />
+    <Compile Include="..\Services\NavigationService.cs" Link="Services\NavigationService.cs" />
+    <Compile Include="..\Services\INavigationService.cs" Link="Services\INavigationService.cs" />
+    <Compile Include="..\Services\AppSession.cs" Link="Services\AppSession.cs" />
+    <Compile Include="..\Services\AuthService.cs" Link="Services\AuthService.cs" />
+    <Compile Include="..\Services\IAuthService.cs" Link="Services\IAuthService.cs" />
+    <Compile Include="..\Services\AuthResult.cs" Link="Services\AuthResult.cs" />
+    <Compile Include="..\Services\AdminAuditService.cs" Link="Services\AdminAuditService.cs" />
+    <Compile Include="..\Services\IAdminAuditService.cs" Link="Services\IAdminAuditService.cs" />
+    <Compile Include="..\Services\IEmployeeLookupService.cs" Link="Services\IEmployeeLookupService.cs" />
+    <Compile Include="..\Services\EmployeeLookupService.cs" Link="Services\EmployeeLookupService.cs" />
+    <Compile Include="..\Services\NoOpEmployeePhotoService.cs" Link="Services\NoOpEmployeePhotoService.cs" />
+    <Compile Include="..\Services\IEmployeePhotoService.cs" Link="Services\IEmployeePhotoService.cs" />
+    <Compile Include="..\Services\IMealScheduleService.cs" Link="Services\IMealScheduleService.cs" />
+    <Compile Include="..\Services\BackendApiMealScheduleService.cs" Link="Services\BackendApiMealScheduleService.cs" />
+    <Compile Include="..\Services\NoOpMealScheduleService.cs" Link="Services\NoOpMealScheduleService.cs" />
+    <Compile Include="..\Services\SiteIdHelper.cs" Link="Services\SiteIdHelper.cs" />
+    <Compile Include="..\Services\AdminLoginHelper.cs" Link="Services\AdminLoginHelper.cs" />
+    <Compile Include="..\Api\ApiDtoMapper.cs" Link="Api\ApiDtoMapper.cs" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Content Include="..\assets\**\*">
+      <Link>assets\%(RecursiveDir)%(Filename)%(Extension)</Link>
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+</Project>

UtopiaCanteen.Client/ViewModels/ClientSettingsViewModel.cs

@@ -0,0 +1,384 @@
+using System.Diagnostics;
+using System.IO;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using UtopiaCanteenSystem.Services;
+using UtopiaCanteenSystem.Services.Logging;
+
+namespace UtopiaCanteen.Client.ViewModels;
+
+public partial class ClientSettingsViewModel : ObservableObject
+{
+    public const string BackendUnavailableMessage =
+        "Backend server unavailable. Please check Backend Server Base URL or server service.";
+
+    private readonly IConfigService _configService;
+    private readonly INavigationService _navigation;
+    private readonly ICanteenBackendApiClient _backendApi;
+    private readonly AppSession _session;
+
+    [ObservableProperty]
+    private string _scanIntervalDays = "0";
+
+    [ObservableProperty]
+    private string _scanIntervalHours = "0";
+
+    [ObservableProperty]
+    private string _scanIntervalMinutes = "0";
+
+    [ObservableProperty]
+    private string _scanIntervalSeconds = "5";
+
+    [ObservableProperty]
+    private string _adminCardId = "ADMIN";
+
+    [ObservableProperty]
+    private string _applicationModeDisplay = "Client";
+
+    [ObservableProperty]
+    private string _backendBaseUrl = string.Empty;
+
+    [ObservableProperty]
+    private string _deviceId = string.Empty;
+
+    [ObservableProperty]
+    private string _siteId = string.Empty;
+
+    [ObservableProperty]
+    private string _backendHealthDisplay = "Checking backend...";
+
+    [ObservableProperty]
+    private bool _isBackendOnline;
+
+    [ObservableProperty]
+    private string _saveMessage = string.Empty;
+
+    [ObservableProperty]
+    private bool _isError;
+
+    [ObservableProperty]
+    private bool _isSaving;
+
+    [ObservableProperty]
+    private bool _isPosting;
+
+    [ObservableProperty]
+    private bool _isSyncingCache;
+
+    [ObservableProperty]
+    private string _lastEmployeeRfidCacheSyncDisplay = "Never";
+
+    [ObservableProperty]
+    private string _lastMealMenuCacheSyncDisplay = "Never";
+
+    public bool HasBackendUrl => !string.IsNullOrWhiteSpace(BackendBaseUrl?.Trim());
+
+    public bool CanPostNow => !IsPosting && HasBackendUrl;
+    public string PostButtonText => IsPosting ? "Posting..." : "Post Data";
+
+    public bool CanSyncCacheNow => !IsSyncingCache && HasBackendUrl;
+    public string SyncCacheButtonText => IsSyncingCache ? "Syncing..." : "Sync Now";
+
+    partial void OnIsPostingChanged(bool value)
+    {
+        OnPropertyChanged(nameof(PostButtonText));
+        OnPropertyChanged(nameof(CanPostNow));
+    }
+
+    partial void OnIsSyncingCacheChanged(bool value)
+    {
+        OnPropertyChanged(nameof(SyncCacheButtonText));
+        OnPropertyChanged(nameof(CanSyncCacheNow));
+    }
+
+    partial void OnBackendBaseUrlChanged(string value)
+    {
+        OnPropertyChanged(nameof(HasBackendUrl));
+        OnPropertyChanged(nameof(CanPostNow));
+        OnPropertyChanged(nameof(CanSyncCacheNow));
+    }
+
+    public ClientSettingsViewModel(
+        IConfigService configService,
+        INavigationService navigation,
+        ICanteenBackendApiClient backendApi,
+        AppSession session)
+    {
+        _configService = configService;
+        _navigation = navigation;
+        _backendApi = backendApi;
+        _session = session;
+        LoadFromConfig();
+        _ = InitializeAsync();
+    }
+
+    public void LoadFromConfig()
+    {
+        ScanIntervalDays = _configService.GetScanIntervalDays().ToString();
+        ScanIntervalHours = _configService.GetScanIntervalHours().ToString();
+        ScanIntervalMinutes = _configService.GetScanIntervalMinutes().ToString();
+        ScanIntervalSeconds = _configService.GetScanIntervalSeconds().ToString();
+        AdminCardId = AdminLoginHelper.ResolveAdminCardIdForDisplay(_configService, _session);
+        ApplicationModeDisplay = "Client";
+        BackendBaseUrl = _configService.GetBackendBaseUrl();
+        DeviceId = _configService.GetDeviceId();
+        SiteId = AdminLoginHelper.FormatSiteIdForDisplay(_configService.GetSiteId());
+        OnPropertyChanged(nameof(HasBackendUrl));
+    }
+
+    public async Task InitializeAsync()
+    {
+        await RefreshBackendStatusAsync().ConfigureAwait(true);
+        await RefreshCacheSyncTimestampsAsync().ConfigureAwait(true);
+    }
+
+    public async Task RefreshBackendStatusAsync()
+    {
+        if (!HasBackendUrl)
+        {
+            IsBackendOnline = false;
+            BackendHealthDisplay = "Backend URL not configured.";
+            return;
+        }
+
+        try
+        {
+            var health = await _backendApi.GetHealthAsync().ConfigureAwait(true);
+            if (health != null && string.Equals(health.Status, "ok", StringComparison.OrdinalIgnoreCase))
+            {
+                IsBackendOnline = true;
+                BackendHealthDisplay = $"Backend online ({health.Mode}) — {health.Utc.ToLocalTime():MM/dd/yyyy hh:mm:ss tt}";
+            }
+            else
+            {
+                IsBackendOnline = false;
+                BackendHealthDisplay = BackendUnavailableMessage;
+            }
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "ClientSettingsViewModel.RefreshBackendStatusAsync");
+            IsBackendOnline = false;
+            BackendHealthDisplay = BackendUnavailableMessage;
+        }
+    }
+
+    public async Task RefreshCacheSyncTimestampsAsync()
+    {
+        if (!HasBackendUrl || !IsBackendOnline)
+            return;
+
+        var status = await _backendApi.GetCacheStatusAsync().ConfigureAwait(true);
+        if (status == null)
+            return;
+
+        LastEmployeeRfidCacheSyncDisplay = FormatSyncTime(status.LastEmployeeRfidCacheSyncUtc);
+        LastMealMenuCacheSyncDisplay = FormatSyncTime(status.LastMealMenuCacheSyncUtc);
+    }
+
+    [RelayCommand]
+    private async Task Save()
+    {
+        IsSaving = true;
+        SaveMessage = string.Empty;
+        IsError = false;
+
+        try
+        {
+            if (!int.TryParse(ScanIntervalDays, out var days) || days < 0 || days > 365)
+            {
+                SetSaveError("Scan interval Days must be 0–365.");
+                return;
+            }
+            if (!int.TryParse(ScanIntervalHours, out var hours) || hours < 0 || hours > 23)
+            {
+                SetSaveError("Scan interval Hours must be 0–23.");
+                return;
+            }
+            if (!int.TryParse(ScanIntervalMinutes, out var minutes) || minutes < 0 || minutes > 59)
+            {
+                SetSaveError("Scan interval Minutes must be 0–59.");
+                return;
+            }
+            if (!int.TryParse(ScanIntervalSeconds, out var seconds) || seconds < 0 || seconds > 59)
+            {
+                SetSaveError("Scan interval Seconds must be 0–59.");
+                return;
+            }
+            if (days == 0 && hours == 0 && minutes == 0 && seconds == 0)
+            {
+                SetSaveError("Scan interval cannot be zero. At least 1 second required.");
+                return;
+            }
+
+            if (string.IsNullOrWhiteSpace(BackendBaseUrl?.Trim()))
+            {
+                SetSaveError("Backend Server Base URL is required.");
+                return;
+            }
+
+            _configService.SetScanIntervalDays(days);
+            _configService.SetScanIntervalHours(hours);
+            _configService.SetScanIntervalMinutes(minutes);
+            _configService.SetScanIntervalSeconds(seconds);
+            _configService.SetAdminCardId(AdminCardId?.Trim() ?? string.Empty);
+            _configService.SetCentralServerBaseUrl(BackendBaseUrl.Trim());
+            _configService.SetDeviceId(DeviceId?.Trim() ?? string.Empty);
+            DeviceId = _configService.GetDeviceId();
+            FileLogger.Info(
+                "ClientSettings",
+                $"Settings saved. AdminCardId={AdminCardId?.Trim()}, SiteId={SiteId?.Trim()}, DeviceId={DeviceId}");
+            var site = SiteId?.Trim() ?? string.Empty;
+            _configService.SetSiteId(
+                string.IsNullOrEmpty(site)
+                    ? string.Empty
+                    : AdminLoginHelper.FormatSiteIdForDisplay(site));
+
+            SaveMessage = "Settings saved.";
+            IsError = false;
+            await RefreshBackendStatusAsync().ConfigureAwait(true);
+        }
+        finally
+        {
+            IsSaving = false;
+        }
+    }
+
+    [RelayCommand]
+    private void Back() => _navigation.NavigateBackFromSettings(_configService.GetScanInterval());
+
+    [RelayCommand]
+    private void OpenMealSchedules() => _navigation.NavigateToMealSchedules();
+
+    [RelayCommand]
+    private void OpenLogsFolder()
+    {
+        try
+        {
+            var dir = LogPaths.ClientLogsDirectory;
+            Directory.CreateDirectory(dir);
+            Process.Start(new ProcessStartInfo
+            {
+                FileName = dir,
+                UseShellExecute = true
+            });
+            FileLogger.Info("ClientSettings", $"Opened logs folder: {dir}");
+        }
+        catch (Exception ex)
+        {
+            FileLogger.Error("ClientSettings", "Failed to open logs folder.", ex);
+            SaveMessage = "Could not open logs folder: " + ex.Message;
+            IsError = true;
+        }
+    }
+
+    [RelayCommand]
+    private async Task SyncEmployeeAndMenuCacheNow()
+    {
+        if (IsSyncingCache)
+            return;
+
+        SaveMessage = "Syncing...";
+        IsError = false;
+        IsSyncingCache = true;
+
+        try
+        {
+            FileLogger.Info("ClientSettings", "Sync Now clicked.");
+            if (!await EnsureBackendAvailableAsync().ConfigureAwait(true))
+                return;
+
+            var url = $"{_configService.GetBackendBaseUrl().TrimEnd('/')}/api/cache/sync-now";
+            FileLogger.Info("ClientSettings", $"Calling POST {url}");
+
+            var result = await _backendApi.SyncCacheNowAsync().ConfigureAwait(true);
+            await RefreshCacheSyncTimestampsAsync().ConfigureAwait(true);
+
+            SaveMessage = result.Message;
+            IsError = !result.Success;
+            FileLogger.Info(
+                "ClientSettings",
+                $"Sync Now response. Success={result.Success}, Message={result.Message}, Details={result.Details}");
+            if (!string.IsNullOrWhiteSpace(result.Details) && result.Success)
+                SaveMessage += " " + result.Details;
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "ClientSettingsViewModel.SyncEmployeeAndMenuCacheNow");
+            SaveMessage = "Cache sync failed: " + ex.Message;
+            IsError = true;
+        }
+        finally
+        {
+            IsSyncingCache = false;
+        }
+    }
+
+    [RelayCommand]
+    private async Task PostDataNow()
+    {
+        if (IsPosting)
+            return;
+
+        SaveMessage = string.Empty;
+        IsError = false;
+        IsPosting = true;
+
+        try
+        {
+            FileLogger.Info("ClientSettings", "Post Data clicked.");
+            if (!await EnsureBackendAvailableAsync().ConfigureAwait(true))
+                return;
+
+            var url = $"{_configService.GetBackendBaseUrl().TrimEnd('/')}/api/orders/sync-now";
+            FileLogger.Info("ClientSettings", $"Calling POST {url}");
+
+            var result = await _backendApi.SyncOrdersNowAsync().ConfigureAwait(true);
+            SaveMessage = result.Message;
+            IsError = !result.Success;
+            FileLogger.Info(
+                "ClientSettings",
+                $"Post Data response. Success={result.Success}, Message={result.Message}, Details={result.Details}");
+            if (!string.IsNullOrWhiteSpace(result.Details) && result.Success)
+                SaveMessage += " " + result.Details;
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "ClientSettingsViewModel.PostDataNow");
+            SaveMessage = "Failed to post data: " + ex.Message;
+            IsError = true;
+        }
+        finally
+        {
+            IsPosting = false;
+        }
+    }
+
+    private async Task<bool> EnsureBackendAvailableAsync()
+    {
+        if (!HasBackendUrl)
+        {
+            SaveMessage = "Backend URL is not configured.";
+            IsError = true;
+            return false;
+        }
+
+        await RefreshBackendStatusAsync().ConfigureAwait(true);
+        if (IsBackendOnline)
+            return true;
+
+        SaveMessage = BackendUnavailableMessage;
+        IsError = true;
+        FileLogger.Warn("ClientSettings", $"Backend unavailable. Url={_configService.GetBackendBaseUrl()}");
+        return false;
+    }
+
+    private void SetSaveError(string message)
+    {
+        SaveMessage = message;
+        IsError = true;
+    }
+
+    private static string FormatSyncTime(DateTime? utc) =>
+        utc == null ? "Never" : utc.Value.ToLocalTime().ToString("MM/dd/yyyy, hh:mm:ss tt");
+}

UtopiaCanteen.Client/Views/ClientSettingsView.xaml

@@ -0,0 +1,413 @@
+<UserControl x:Class="UtopiaCanteen.Client.Views.ClientSettingsView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             HorizontalAlignment="Stretch"
+             VerticalAlignment="Stretch"
+             HorizontalContentAlignment="Stretch"
+             VerticalContentAlignment="Stretch">
+    <UserControl.Resources>
+        <BooleanToVisibilityConverter x:Key="BoolToVis"/>
+        <SolidColorBrush x:Key="AppBackground" Color="#F0F2F5"/>
+        <SolidColorBrush x:Key="CardBackground" Color="#FFFFFF"/>
+        <SolidColorBrush x:Key="PrimaryText" Color="#2D3748"/>
+        <SolidColorBrush x:Key="MutedText" Color="#718096"/>
+        <SolidColorBrush x:Key="PrimaryAccent" Color="#5BA3A0"/>
+        <SolidColorBrush x:Key="PrimaryHover" Color="#4a918e"/>
+        <SolidColorBrush x:Key="SuccessBrush" Color="#38A169"/>
+        <SolidColorBrush x:Key="ErrorBrush" Color="#E53E3E"/>
+        <SolidColorBrush x:Key="BorderBrush" Color="#E2E8F0"/>
+        <SolidColorBrush x:Key="OrangeAccent" Color="#ED8936"/>
+        <SolidColorBrush x:Key="CardHeaderBg" Color="#F7FAFC"/>
+
+        <Style x:Key="SectionCardStyle" TargetType="Border">
+            <Setter Property="Background" Value="{StaticResource CardBackground}"/>
+            <Setter Property="CornerRadius" Value="12"/>
+            <Setter Property="BorderBrush" Value="{StaticResource BorderBrush}"/>
+            <Setter Property="BorderThickness" Value="1"/>
+            <Setter Property="Padding" Value="24"/>
+            <Setter Property="Margin" Value="0,0,0,16"/>
+            <Setter Property="HorizontalAlignment" Value="Stretch"/>
+        </Style>
+
+        <Style x:Key="ModernTextBoxStyle" TargetType="TextBox">
+            <Setter Property="HorizontalAlignment" Value="Stretch"/>
+            <Setter Property="MinHeight" Value="48"/>
+            <Setter Property="Background" Value="White"/>
+            <Setter Property="BorderThickness" Value="1"/>
+            <Setter Property="BorderBrush" Value="#E2E8F0"/>
+            <Setter Property="Foreground" Value="#0A1628"/>
+            <Setter Property="FontSize" Value="16"/>
+            <Setter Property="Padding" Value="14,0"/>
+            <Setter Property="VerticalContentAlignment" Value="Center"/>
+        </Style>
+
+        <Style x:Key="PrimaryButtonStyle" TargetType="Button">
+            <Setter Property="Background" Value="{StaticResource PrimaryAccent}"/>
+            <Setter Property="Foreground" Value="White"/>
+            <Setter Property="BorderThickness" Value="0"/>
+            <Setter Property="FontSize" Value="15"/>
+            <Setter Property="FontWeight" Value="SemiBold"/>
+            <Setter Property="Padding" Value="20,10"/>
+            <Setter Property="MinHeight" Value="42"/>
+            <Setter Property="Cursor" Value="Hand"/>
+        </Style>
+
+        <Style x:Key="OutlineButtonStyle" TargetType="Button">
+            <Setter Property="Background" Value="White"/>
+            <Setter Property="Foreground" Value="{StaticResource PrimaryText}"/>
+            <Setter Property="BorderBrush" Value="{StaticResource BorderBrush}"/>
+            <Setter Property="BorderThickness" Value="1"/>
+            <Setter Property="FontSize" Value="15"/>
+            <Setter Property="FontWeight" Value="SemiBold"/>
+            <Setter Property="Padding" Value="20,10"/>
+            <Setter Property="MinHeight" Value="42"/>
+            <Setter Property="Cursor" Value="Hand"/>
+        </Style>
+
+        <Style x:Key="SyncSubCardStyle" TargetType="Border">
+            <Setter Property="Background" Value="{StaticResource CardHeaderBg}"/>
+            <Setter Property="CornerRadius" Value="10"/>
+            <Setter Property="BorderBrush" Value="{StaticResource BorderBrush}"/>
+            <Setter Property="BorderThickness" Value="1"/>
+            <Setter Property="Padding" Value="20"/>
+            <Setter Property="HorizontalAlignment" Value="Stretch"/>
+        </Style>
+
+        <Style x:Key="SettingsTabItemStyle" TargetType="TabItem">
+            <Setter Property="Foreground" Value="{StaticResource MutedText}"/>
+            <Setter Property="FontSize" Value="15"/>
+            <Setter Property="FontWeight" Value="SemiBold"/>
+            <Setter Property="Padding" Value="18,10"/>
+            <Setter Property="Margin" Value="0,0,8,0"/>
+            <Setter Property="Template">
+                <Setter.Value>
+                    <ControlTemplate TargetType="TabItem">
+                        <Border x:Name="TabBorder"
+                                Background="Transparent"
+                                BorderBrush="Transparent"
+                                BorderThickness="0,0,0,3"
+                                Padding="{TemplateBinding Padding}">
+                            <ContentPresenter ContentSource="Header"
+                                              HorizontalAlignment="Center"
+                                              VerticalAlignment="Center"/>
+                        </Border>
+                        <ControlTemplate.Triggers>
+                            <Trigger Property="IsMouseOver" Value="True">
+                                <Setter TargetName="TabBorder" Property="Background" Value="#F7FAFC"/>
+                                <Setter Property="Foreground" Value="{StaticResource PrimaryText}"/>
+                            </Trigger>
+                            <Trigger Property="IsSelected" Value="True">
+                                <Setter TargetName="TabBorder" Property="Background" Value="#E6F4F3"/>
+                                <Setter TargetName="TabBorder" Property="BorderBrush" Value="{StaticResource PrimaryAccent}"/>
+                                <Setter Property="Foreground" Value="{StaticResource PrimaryAccent}"/>
+                            </Trigger>
+                        </ControlTemplate.Triggers>
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style>
+    </UserControl.Resources>
+
+    <Grid Background="{StaticResource AppBackground}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="*"/>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="Auto"/>
+        </Grid.RowDefinitions>
+
+        <StackPanel Grid.Row="0" Orientation="Horizontal" Margin="32,24,32,12">
+            <Border Width="48" Height="48" Background="#E6F4F3" CornerRadius="24" Margin="0,0,16,0">
+                <Viewbox Margin="10">
+                    <Canvas Width="24" Height="24">
+                        <Path Data="M12,15.5A3.5,3.5 0 0,1 8.5,12A3.5,3.5 0 0,1 12,8.5A3.5,3.5 0 0,1 15.5,12A3.5,3.5 0 0,1 12,15.5M19.43,12.97C19.47,12.65 19.5,12.33 19.5,12C19.5,11.67 19.47,11.34 19.43,11.03L21.54,9.37C21.73,9.22 21.78,8.95 21.66,8.73L19.66,5.27C19.54,5.05 19.27,4.96 19.05,5.05L16.56,6.26C16.04,5.86 15.48,5.51 14.87,5.23L14.5,2.58C14.46,2.34 14.25,2.17 14,2.17H10C9.75,2.17 9.54,2.34 9.5,2.58L9.13,5.23C8.52,5.51 7.96,5.86 7.44,6.26L4.95,5.05C4.73,4.96 4.46,5.05 4.34,5.27L2.34,8.73C2.22,8.95 2.27,9.22 2.46,9.37L4.57,11.03C4.53,11.34 4.5,11.67 4.5,12C4.5,12.33 4.53,12.65 4.57,12.97L2.46,14.63C2.27,14.78 2.22,15.05 2.34,15.27L4.34,18.73C4.46,18.95 4.73,19.03 4.95,18.95L7.44,17.74C7.96,18.14 8.52,18.49 9.13,18.77L9.5,21.42C9.54,21.66 9.75,21.83 10,21.83H14C14.25,21.83 14.46,21.66 14.5,21.42L14.87,18.77C15.48,18.49 16.04,18.14 16.56,17.74L19.05,18.95C19.27,19.03 19.54,18.95 19.66,18.73L21.66,15.27C21.78,15.05 21.73,14.78 21.54,14.63L19.43,12.97Z"
+                              Fill="{StaticResource PrimaryAccent}" Stretch="Uniform"/>
+                    </Canvas>
+                </Viewbox>
+            </Border>
+            <StackPanel VerticalAlignment="Center">
+                <TextBlock Text="Settings" FontSize="32" FontWeight="Bold" Foreground="{StaticResource PrimaryText}"/>
+                <TextBlock Text="Configure scanning, access, connectivity, and sync settings."
+                           FontSize="15" Foreground="{StaticResource MutedText}" Margin="0,4,0,0"/>
+            </StackPanel>
+        </StackPanel>
+
+        <TabControl Grid.Row="1"
+                    Margin="32,0,32,0"
+                    Background="Transparent"
+                    BorderThickness="0"
+                    ItemContainerStyle="{StaticResource SettingsTabItemStyle}">
+            <TabControl.Resources>
+                <Style TargetType="TabPanel">
+                    <Setter Property="Margin" Value="0,0,0,16"/>
+                </Style>
+            </TabControl.Resources>
+
+            <TabItem Header="General">
+                <ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Disabled">
+                    <StackPanel>
+                        <Border Style="{StaticResource SectionCardStyle}">
+                            <StackPanel>
+                                <StackPanel Orientation="Horizontal" Margin="0,0,0,12">
+                                    <Border Width="36" Height="36" Background="#E6F4F3" CornerRadius="18" Margin="0,0,12,0">
+                                        <TextBlock Text="&#xE121;" FontFamily="Segoe MDL2 Assets" FontSize="16"
+                                                   Foreground="{StaticResource PrimaryAccent}" HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                                    </Border>
+                                    <StackPanel VerticalAlignment="Center">
+                                        <TextBlock Text="Scan Interval" FontSize="20" FontWeight="Bold" Foreground="{StaticResource PrimaryText}"/>
+                                        <TextBlock Text="Set the minimum time between scans to prevent duplicates."
+                                                   FontSize="14" Foreground="{StaticResource MutedText}"/>
+                                    </StackPanel>
+                                </StackPanel>
+                                <Grid Margin="0,8,0,0">
+                                    <Grid.ColumnDefinitions>
+                                        <ColumnDefinition Width="*"/><ColumnDefinition Width="12"/>
+                                        <ColumnDefinition Width="*"/><ColumnDefinition Width="12"/>
+                                        <ColumnDefinition Width="*"/><ColumnDefinition Width="12"/>
+                                        <ColumnDefinition Width="*"/>
+                                    </Grid.ColumnDefinitions>
+                                    <StackPanel Grid.Column="0">
+                                        <TextBlock Text="Days (0-365)" FontSize="13" Foreground="{StaticResource MutedText}" Margin="0,0,0,4"/>
+                                        <TextBox Text="{Binding ScanIntervalDays, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource ModernTextBoxStyle}"/>
+                                    </StackPanel>
+                                    <StackPanel Grid.Column="2">
+                                        <TextBlock Text="Hours (0-23)" FontSize="13" Foreground="{StaticResource MutedText}" Margin="0,0,0,4"/>
+                                        <TextBox Text="{Binding ScanIntervalHours, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource ModernTextBoxStyle}"/>
+                                    </StackPanel>
+                                    <StackPanel Grid.Column="4">
+                                        <TextBlock Text="Minutes (0-59)" FontSize="13" Foreground="{StaticResource MutedText}" Margin="0,0,0,4"/>
+                                        <TextBox Text="{Binding ScanIntervalMinutes, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource ModernTextBoxStyle}"/>
+                                    </StackPanel>
+                                    <StackPanel Grid.Column="6">
+                                        <TextBlock Text="Seconds (0-59)" FontSize="13" Foreground="{StaticResource MutedText}" Margin="0,0,0,4"/>
+                                        <TextBox Text="{Binding ScanIntervalSeconds, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource ModernTextBoxStyle}"/>
+                                    </StackPanel>
+                                </Grid>
+                                <StackPanel Orientation="Horizontal" Margin="0,12,0,0">
+                                    <TextBlock Text="&#xE946;" FontFamily="Segoe MDL2 Assets" FontSize="14"
+                                               Foreground="{StaticResource MutedText}" Margin="0,2,8,0"/>
+                                    <TextBlock Text="The minimum time between scans to prevent duplicates. At least 1 second required."
+                                               FontSize="13" Foreground="{StaticResource MutedText}" TextWrapping="Wrap"/>
+                                </StackPanel>
+                            </StackPanel>
+                        </Border>
+
+                        <Border Style="{StaticResource SectionCardStyle}">
+                            <StackPanel>
+                                <StackPanel Orientation="Horizontal" Margin="0,0,0,12">
+                                    <Border Width="36" Height="36" Background="#E6F4F3" CornerRadius="18" Margin="0,0,12,0">
+                                        <TextBlock Text="&#xE77B;" FontFamily="Segoe MDL2 Assets" FontSize="16"
+                                                   Foreground="{StaticResource PrimaryAccent}" HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                                    </Border>
+                                    <TextBlock Text="Admin Access" FontSize="20" FontWeight="Bold" Foreground="{StaticResource PrimaryText}" VerticalAlignment="Center"/>
+                                </StackPanel>
+                                <TextBlock Text="Admin Employee ID" FontSize="14" FontWeight="SemiBold" Foreground="{StaticResource PrimaryText}"/>
+                                <TextBox Text="{Binding AdminCardId, UpdateSourceTrigger=PropertyChanged}"
+                                         IsReadOnly="True"
+                                         IsTabStop="False"
+                                         Style="{StaticResource ModernTextBoxStyle}" Margin="0,8,0,4" Background="#F8FAFC"/>
+                                <TextBlock Text="Card ID with admin access to settings." FontSize="13" Foreground="{StaticResource MutedText}"/>
+                            </StackPanel>
+                        </Border>
+                    </StackPanel>
+                </ScrollViewer>
+            </TabItem>
+
+            <TabItem Header="Mode &amp; Connectivity">
+                <ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Disabled">
+                    <Border Style="{StaticResource SectionCardStyle}">
+                        <StackPanel>
+                            <StackPanel Orientation="Horizontal" Margin="0,0,0,12">
+                                <Border Width="36" Height="36" Background="#E6F4F3" CornerRadius="18" Margin="0,0,12,0">
+                                    <TextBlock Text="&#xE968;" FontFamily="Segoe MDL2 Assets" FontSize="16"
+                                               Foreground="{StaticResource PrimaryAccent}" HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                                </Border>
+                                <StackPanel VerticalAlignment="Center">
+                                    <TextBlock Text="Application Mode &amp; Connectivity" FontSize="20" FontWeight="Bold" Foreground="{StaticResource PrimaryText}"/>
+                                    <TextBlock Text="Configure how this application connects to servers."
+                                               FontSize="14" Foreground="{StaticResource MutedText}"/>
+                                </StackPanel>
+                            </StackPanel>
+
+                            <Grid>
+                                <Grid.RowDefinitions>
+                                    <RowDefinition Height="Auto"/>
+                                    <RowDefinition Height="Auto"/>
+                                </Grid.RowDefinitions>
+                                <Grid.ColumnDefinitions>
+                                    <ColumnDefinition Width="*"/>
+                                    <ColumnDefinition Width="24"/>
+                                    <ColumnDefinition Width="2*"/>
+                                    <ColumnDefinition Width="24"/>
+                                    <ColumnDefinition Width="*"/>
+                                </Grid.ColumnDefinitions>
+                                <StackPanel Grid.Row="0" Grid.Column="0">
+                                    <TextBlock Text="Application Mode" FontSize="14" FontWeight="SemiBold" Foreground="{StaticResource PrimaryText}"/>
+                                    <TextBox Text="{Binding ApplicationModeDisplay}" IsReadOnly="True" IsTabStop="False"
+                                             Style="{StaticResource ModernTextBoxStyle}" Margin="0,8,0,4" Background="#F8FAFC"/>
+                                    <TextBlock Text="Client: this PC sends scans to the central backend server."
+                                               FontSize="12" Foreground="{StaticResource MutedText}" TextWrapping="Wrap"/>
+                                </StackPanel>
+                                <StackPanel Grid.Row="0" Grid.Column="2">
+                                    <TextBlock Text="Backend Server Base URL" FontSize="14" FontWeight="SemiBold" Foreground="{StaticResource PrimaryText}"/>
+                                    <TextBox Text="{Binding BackendBaseUrl, UpdateSourceTrigger=PropertyChanged}"
+                                             Style="{StaticResource ModernTextBoxStyle}" Margin="0,8,0,4"/>
+                                    <TextBlock Text="Example: http://192.168.1.10:5000" FontSize="12" Foreground="{StaticResource MutedText}"/>
+                                </StackPanel>
+                                <StackPanel Grid.Row="0" Grid.Column="4">
+                                    <TextBlock Text="Device ID" FontSize="14" FontWeight="SemiBold" Foreground="{StaticResource PrimaryText}"/>
+                                    <TextBox Text="{Binding DeviceId, UpdateSourceTrigger=PropertyChanged}"
+                                             IsReadOnly="True"
+                                             IsTabStop="False"
+                                             Style="{StaticResource ModernTextBoxStyle}" Margin="0,8,0,4" Background="#F8FAFC"/>
+                                    <TextBlock Text="Identifies this scanner PC in scan records." FontSize="12" Foreground="{StaticResource MutedText}"/>
+                                </StackPanel>
+                                <StackPanel Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="3" Margin="0,16,0,0">
+                                    <TextBlock Text="Site ID" FontSize="14" FontWeight="SemiBold" Foreground="{StaticResource PrimaryText}"/>
+                                    <TextBox Text="{Binding SiteId, UpdateSourceTrigger=PropertyChanged}"
+                                             IsReadOnly="True"
+                                             IsTabStop="False"
+                                             Style="{StaticResource ModernTextBoxStyle}" Margin="0,8,0,4" MaxWidth="480" HorizontalAlignment="Left" Background="#F8FAFC"/>
+                                    <TextBlock Text="Canteen location site code sent with each scan." FontSize="12" Foreground="{StaticResource MutedText}"/>
+                                </StackPanel>
+                            </Grid>
+
+                            <Border Margin="0,16,0,0" Padding="12" CornerRadius="8" Background="#EDF2F7">
+                                <StackPanel Orientation="Horizontal">
+                                    <Ellipse Width="10" Height="10" Margin="0,4,10,0" VerticalAlignment="Top">
+                                        <Ellipse.Style>
+                                            <Style TargetType="Ellipse">
+                                                <Setter Property="Fill" Value="{StaticResource ErrorBrush}"/>
+                                                <Style.Triggers>
+                                                    <DataTrigger Binding="{Binding IsBackendOnline}" Value="True">
+                                                        <Setter Property="Fill" Value="{StaticResource SuccessBrush}"/>
+                                                    </DataTrigger>
+                                                </Style.Triggers>
+                                            </Style>
+                                        </Ellipse.Style>
+                                    </Ellipse>
+                                    <TextBlock Text="{Binding BackendHealthDisplay}" FontSize="13" Foreground="{StaticResource PrimaryText}" TextWrapping="Wrap"/>
+                                </StackPanel>
+                            </Border>
+                        </StackPanel>
+                    </Border>
+                </ScrollViewer>
+            </TabItem>
+
+            <TabItem Header="Data Sync">
+                <ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Disabled">
+                    <Border Style="{StaticResource SectionCardStyle}" Margin="0,0,0,8">
+                        <StackPanel>
+                            <StackPanel Orientation="Horizontal" Margin="0,0,0,16">
+                                <Border Width="36" Height="36" Background="#E6F4F3" CornerRadius="18" Margin="0,0,12,0">
+                                    <TextBlock Text="&#xE895;" FontFamily="Segoe MDL2 Assets" FontSize="16"
+                                               Foreground="{StaticResource PrimaryAccent}" HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                                </Border>
+                                <StackPanel VerticalAlignment="Center">
+                                    <TextBlock Text="Data Sync" FontSize="20" FontWeight="Bold" Foreground="{StaticResource PrimaryText}"/>
+                                    <TextBlock Text="Keep your offline data up to date and send transactions to production."
+                                               FontSize="14" Foreground="{StaticResource MutedText}"/>
+                                </StackPanel>
+                            </StackPanel>
+                            <Grid>
+                                <Grid.ColumnDefinitions>
+                                    <ColumnDefinition Width="*"/><ColumnDefinition Width="16"/><ColumnDefinition Width="*"/>
+                                </Grid.ColumnDefinitions>
+                                <Border Grid.Column="0" Style="{StaticResource SyncSubCardStyle}">
+                                    <StackPanel>
+                                        <StackPanel Orientation="Horizontal" Margin="0,0,0,8">
+                                            <TextBlock Text="&#xE896;" FontFamily="Segoe MDL2 Assets" FontSize="18"
+                                                       Foreground="{StaticResource PrimaryAccent}" Margin="0,0,8,0"/>
+                                            <TextBlock Text="Download Offline Data" FontSize="17" FontWeight="SemiBold" Foreground="{StaticResource PrimaryText}"/>
+                                        </StackPanel>
+                                        <TextBlock Text="Download employee RFID tags, meal schedules, and menu data for offline scanning."
+                                                   FontSize="13" Foreground="{StaticResource MutedText}" TextWrapping="Wrap" Margin="0,0,0,16"/>
+                                        <Button Content="{Binding SyncCacheButtonText}"
+                                                Command="{Binding SyncEmployeeAndMenuCacheNowCommand}"
+                                                Style="{StaticResource PrimaryButtonStyle}"
+                                                HorizontalAlignment="Left"
+                                                IsEnabled="{Binding CanSyncCacheNow}"/>
+                                    </StackPanel>
+                                </Border>
+                                <Border Grid.Column="2" Style="{StaticResource SyncSubCardStyle}">
+                                    <StackPanel>
+                                        <StackPanel Orientation="Horizontal" Margin="0,0,0,8">
+                                            <TextBlock Text="&#xE898;" FontFamily="Segoe MDL2 Assets" FontSize="18"
+                                                       Foreground="{StaticResource OrangeAccent}" Margin="0,0,8,0"/>
+                                            <TextBlock Text="Post Data to Production" FontSize="17" FontWeight="SemiBold" Foreground="{StaticResource PrimaryText}"/>
+                                        </StackPanel>
+                                        <TextBlock Text="Post captured scan and transaction data to the production server."
+                                                   FontSize="13" Foreground="{StaticResource MutedText}" TextWrapping="Wrap" Margin="0,0,0,16"/>
+                                        <Button Content="{Binding PostButtonText}"
+                                                Command="{Binding PostDataNowCommand}"
+                                                Style="{StaticResource PrimaryButtonStyle}"
+                                                HorizontalAlignment="Left"
+                                                IsEnabled="{Binding CanPostNow}"/>
+                                    </StackPanel>
+                                </Border>
+                            </Grid>
+                            <TextBlock Text="{Binding LastEmployeeRfidCacheSyncDisplay, StringFormat=Last employee RFID cache sync: {0}}"
+                                       FontSize="13" Foreground="{StaticResource MutedText}" Margin="0,16,0,4"/>
+                            <TextBlock Text="{Binding LastMealMenuCacheSyncDisplay, StringFormat=Last meal/menu cache sync: {0}}"
+                                       FontSize="13" Foreground="{StaticResource MutedText}"/>
+                        </StackPanel>
+                    </Border>
+                </ScrollViewer>
+            </TabItem>
+        </TabControl>
+
+        <Border Grid.Row="2" Padding="14" CornerRadius="8" Margin="32,8,32,12">
+            <Border.Style>
+                <Style TargetType="Border">
+                    <Setter Property="Background" Value="#dcfce7"/>
+                    <Setter Property="BorderBrush" Value="#86efac"/>
+                    <Setter Property="BorderThickness" Value="1"/>
+                    <Setter Property="Visibility" Value="Visible"/>
+                    <Style.Triggers>
+                        <DataTrigger Binding="{Binding SaveMessage}" Value="">
+                            <Setter Property="Visibility" Value="Collapsed"/>
+                        </DataTrigger>
+                        <DataTrigger Binding="{Binding IsError}" Value="True">
+                            <Setter Property="Background" Value="#fee2e2"/>
+                            <Setter Property="BorderBrush" Value="#fca5a5"/>
+                        </DataTrigger>
+                    </Style.Triggers>
+                </Style>
+            </Border.Style>
+            <TextBlock Text="{Binding SaveMessage}" FontSize="15" FontWeight="SemiBold" TextWrapping="Wrap">
+                <TextBlock.Style>
+                    <Style TargetType="TextBlock">
+                        <Setter Property="Foreground" Value="{StaticResource SuccessBrush}"/>
+                        <Style.Triggers>
+                            <DataTrigger Binding="{Binding IsError}" Value="True">
+                                <Setter Property="Foreground" Value="{StaticResource ErrorBrush}"/>
+                            </DataTrigger>
+                        </Style.Triggers>
+                    </Style>
+                </TextBlock.Style>
+            </TextBlock>
+        </Border>
+
+        <Border Grid.Row="3" Background="#F9FBFB" BorderBrush="{StaticResource BorderBrush}" BorderThickness="0,1,0,0" Padding="32,16">
+            <Grid HorizontalAlignment="Stretch">
+                <StackPanel Orientation="Horizontal" HorizontalAlignment="Right">
+                    <Button Command="{Binding OpenMealSchedulesCommand}" Style="{StaticResource OutlineButtonStyle}" MinWidth="160" Margin="0,0,12,0">
+                        <StackPanel Orientation="Horizontal">
+                            <TextBlock Text="&#xE787;" FontFamily="Segoe MDL2 Assets" FontSize="14" Margin="0,0,8,0" VerticalAlignment="Center"/>
+                            <TextBlock Text="Meal Schedules" VerticalAlignment="Center"/>
+                        </StackPanel>
+                    </Button>
+                    <Button Content="Open Logs Folder" Command="{Binding OpenLogsFolderCommand}"
+                            Style="{StaticResource OutlineButtonStyle}" MinWidth="140" Margin="0,0,12,0"/>
+                    <Button Content="Back" Command="{Binding BackCommand}" Style="{StaticResource OutlineButtonStyle}" MinWidth="100" Margin="0,0,12,0"/>
+                    <Button Command="{Binding SaveCommand}" Style="{StaticResource PrimaryButtonStyle}" MinWidth="100">
+                        <StackPanel Orientation="Horizontal">
+                            <TextBlock Text="&#xE74E;" FontFamily="Segoe MDL2 Assets" FontSize="14" Margin="0,0,8,0" VerticalAlignment="Center"/>
+                            <TextBlock Text="Save" VerticalAlignment="Center"/>
+                        </StackPanel>
+                    </Button>
+                </StackPanel>
+            </Grid>
+        </Border>
+    </Grid>
+</UserControl>

UtopiaCanteen.Client/Views/ClientSettingsView.xaml.cs

@@ -0,0 +1,19 @@
+using System.Windows.Controls;
+using UtopiaCanteen.Client.ViewModels;
+
+namespace UtopiaCanteen.Client.Views;
+
+public partial class ClientSettingsView : UserControl
+{
+    public ClientSettingsView()
+    {
+        InitializeComponent();
+    }
+
+    public ClientSettingsView(ClientSettingsViewModel viewModel)
+    {
+        InitializeComponent();
+        DataContext = viewModel;
+        Loaded += (_, _) => _ = viewModel.InitializeAsync();
+    }
+}

UtopiaCanteen.Shared/CacheStatusResponse.cs

@@ -0,0 +1,7 @@
+namespace UtopiaCanteen.Shared;
+
+public sealed class CacheStatusResponse
+{
+    public DateTime? LastEmployeeRfidCacheSyncUtc { get; set; }
+    public DateTime? LastMealMenuCacheSyncUtc { get; set; }
+}

UtopiaCanteen.Shared/EmployeeDto.cs

@@ -0,0 +1,18 @@
+namespace UtopiaCanteen.Shared;
+
+public sealed class EmployeeDto
+{
+    public string ParentDocumentId { get; set; } = string.Empty;
+    public string EmployeeId { get; set; } = string.Empty;
+    public string UindSerial { get; set; } = string.Empty;
+    public int FunctionId { get; set; }
+    public int DepartmentId { get; set; }
+    public DateTime? TagCreatedAtUtc { get; set; }
+    public string TagCreatedBy { get; set; } = string.Empty;
+    public string FirstName { get; set; } = string.Empty;
+    public string MiddleName { get; set; } = string.Empty;
+    public string DepartmentTitle { get; set; } = string.Empty;
+    public string DepartmentType { get; set; } = string.Empty;
+    public string LocationSiteId { get; set; } = string.Empty;
+    public string GradeType { get; set; } = string.Empty;
+}

UtopiaCanteen.Shared/EmployeeLocationSiteResponse.cs

@@ -0,0 +1,6 @@
+namespace UtopiaCanteen.Shared;
+
+public sealed class EmployeeLocationSiteResponse
+{
+    public string? LocationSiteId { get; set; }
+}

UtopiaCanteen.Shared/HealthResponse.cs

@@ -0,0 +1,8 @@
+namespace UtopiaCanteen.Shared;
+
+public sealed class HealthResponse
+{
+    public string Status { get; set; } = "ok";
+    public string Mode { get; set; } = "server";
+    public DateTime Utc { get; set; }
+}

UtopiaCanteen.Shared/ManualSyncResponse.cs

@@ -0,0 +1,10 @@
+namespace UtopiaCanteen.Shared;
+
+public sealed class ManualSyncResponse
+{
+    public bool Success { get; set; }
+    public string Message { get; set; } = string.Empty;
+    public DateTime? StartedAt { get; set; }
+    public DateTime? CompletedAt { get; set; }
+    public string? Details { get; set; }
+}

UtopiaCanteen.Shared/MealScheduleDto.cs

@@ -0,0 +1,14 @@
+namespace UtopiaCanteen.Shared;
+
+public sealed class MealScheduleDto
+{
+    public long Id { get; set; }
+    public string MealName { get; set; } = string.Empty;
+    public string LocationSiteId { get; set; } = string.Empty;
+    public int MealSession { get; set; }
+    public string StartTime { get; set; } = string.Empty;
+    public string EndTime { get; set; } = string.Empty;
+    public bool IsActive { get; set; } = true;
+    public DateTime CreatedAt { get; set; }
+    public DateTime UpdatedAt { get; set; }
+}

UtopiaCanteen.Shared/RecentScanDto.cs

@@ -0,0 +1,31 @@
+using System.Text.Json.Serialization;
+
+namespace UtopiaCanteen.Shared;
+
+public sealed class RecentScanDto
+{
+    public int Id { get; set; }
+    public string CardId { get; set; } = string.Empty;
+    public DateTime ScanTime { get; set; }
+    public bool IsSynced { get; set; }
+    public string SiteId { get; set; } = string.Empty;
+    public string DeviceId { get; set; } = string.Empty;
+    public string IpAddress { get; set; } = string.Empty;
+    public int MealSessionCode { get; set; }
+    public string ParentDocumentId { get; set; } = string.Empty;
+    public string EmployeeId { get; set; } = string.Empty;
+    public string UindSerial { get; set; } = string.Empty;
+    public int FunctionId { get; set; }
+    public int DepartmentId { get; set; }
+    public DateTime? TagCreatedAtUtc { get; set; }
+    public string TagCreatedBy { get; set; } = string.Empty;
+    public string EmployeeName { get; set; } = string.Empty;
+    public string Department { get; set; } = string.Empty;
+    public string DepartmentType { get; set; } = string.Empty;
+    public string MealLabel { get; set; } = string.Empty;
+    public string MealItems { get; set; } = string.Empty;
+    public double TotalPrice { get; set; }
+
+    [JsonPropertyName("grade_type")]
+    public string GradeType { get; set; } = string.Empty;
+}

UtopiaCanteen.Shared/ScanRequest.cs

@@ -0,0 +1,9 @@
+namespace UtopiaCanteen.Shared;
+
+public sealed class ScanRequest
+{
+    public string CardId { get; set; } = string.Empty;
+    public string DeviceId { get; set; } = string.Empty;
+    public string SiteId { get; set; } = string.Empty;
+    public string? IpAddress { get; set; }
+}

UtopiaCanteen.Shared/ScanResponse.cs

@@ -0,0 +1,15 @@
+namespace UtopiaCanteen.Shared;
+
+public sealed class ScanResponse
+{
+    public bool Success { get; set; }
+    public string Message { get; set; } = string.Empty;
+    public int CooldownSecondsRemaining { get; set; }
+    public EmployeeDto? Employee { get; set; }
+    public int MealSession { get; set; }
+    public string? EmployeeSiteId { get; set; }
+    public string? CurrentSiteId { get; set; }
+    public string? MealLabel { get; set; }
+    public string? MealItems { get; set; }
+    public double TotalPrice { get; set; }
+}

UtopiaCanteen.Shared/StatsDto.cs

@@ -0,0 +1,6 @@
+namespace UtopiaCanteen.Shared;
+
+public sealed class StatsDto
+{
+    public int Count { get; set; }
+}

UtopiaCanteen.Shared/UtopiaCanteen.Shared.csproj

@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <RootNamespace>UtopiaCanteen.Shared</RootNamespace>
+    <AssemblyName>UtopiaCanteen.Shared</AssemblyName>
+  </PropertyGroup>
+</Project>

UtopiaCanteen.sln

@@ -0,0 +1,43 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31903.59
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "UtopiaCanteen.Shared", "UtopiaCanteen.Shared\UtopiaCanteen.Shared.csproj", "{B1B2C3D4-E5F6-7890-ABCD-EF1234567891}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "UtopiaCanteen.Backend", "UtopiaCanteen.Backend\UtopiaCanteen.Backend.csproj", "{B1B2C3D4-E5F6-7890-ABCD-EF1234567892}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "UtopiaCanteen.BackendService", "UtopiaCanteen.BackendService\UtopiaCanteen.BackendService.csproj", "{B1B2C3D4-E5F6-7890-ABCD-EF1234567893}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "UtopiaCanteen.Client", "UtopiaCanteen.Client\UtopiaCanteen.Client.csproj", "{B1B2C3D4-E5F6-7890-ABCD-EF1234567894}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "UtopiaCanteenSystem", "UtopiaCanteenSystem.csproj", "{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567891}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567891}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567891}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567891}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567892}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567892}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567892}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567892}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567893}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567893}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567893}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567893}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567894}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567894}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567894}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B1B2C3D4-E5F6-7890-ABCD-EF1234567894}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A1B2C3D4-E5F6-7890-ABCD-EF1234567890}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal

UtopiaCanteenSystem.csproj

@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
+    <EnableDefaultCompileItems>true</EnableDefaultCompileItems>
     <TargetFramework>net8.0-windows</TargetFramework>
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
@@ -13,6 +14,13 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <Compile Remove="UtopiaCanteen.Shared\**" />
+    <Compile Remove="UtopiaCanteen.Backend\**" />
+    <Compile Remove="UtopiaCanteen.BackendService\**" />
+    <Compile Remove="UtopiaCanteen.Client\**" />
+    <Page Remove="UtopiaCanteen.Client\**" />
+    <ApplicationDefinition Remove="UtopiaCanteen.Client\**" />
+    <ProjectReference Include="UtopiaCanteen.Shared\UtopiaCanteen.Shared.csproj" />
     <PackageReference Include="CommunityToolkit.Mvvm" Version="8.2.2" />
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.11" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="8.0.11" />

ViewModels/AdminLoginViewModel.cs

@@ -1,6 +1,7 @@
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using UtopiaCanteenSystem.Services;
+using UtopiaCanteenSystem.Services.Logging;
 
 namespace UtopiaCanteenSystem.ViewModels;
 
@@ -12,6 +13,7 @@ public partial class AdminLoginViewModel : ObservableObject
     private readonly IConfigService _config;
     private readonly IAdminAuditService _adminAudit;
     private readonly IEmployeeLookupService _employeeLookup;
+    private readonly ICanteenBackendApiClient? _backendApi;
 
     [ObservableProperty]
     private string _username = string.Empty;
@@ -35,7 +37,8 @@ public partial class AdminLoginViewModel : ObservableObject
         INavigationService navigation,
         IConfigService config,
         IAdminAuditService adminAudit,
-        IEmployeeLookupService employeeLookup)
+        IEmployeeLookupService employeeLookup,
+        ICanteenBackendApiClient? backendApi = null)
     {
         _authService = authService;
         _session = session;
@@ -43,6 +46,7 @@ public partial class AdminLoginViewModel : ObservableObject
         _config = config;
         _adminAudit = adminAudit;
         _employeeLookup = employeeLookup;
+        _backendApi = backendApi;
 
         RememberCredentials = _config.GetRememberAdminCredentials();
         if (RememberCredentials)
@@ -81,20 +85,21 @@ public partial class AdminLoginViewModel : ObservableObject
             if (!result.Success)
             {
                 ErrorMessage = "Invalid username or password.";
+                FileLogger.Warn("ClientLogin", $"Admin login failed for user '{user}'.");
                 return;
             }
 
             _session.SetAdminAuthenticated(user, result.EmployeeId);
 
-            try
+            await AdminLoginHelper.ApplyAdminLoginDefaultsAsync(
-            {
+                result.EmployeeId,
-                var siteId = await _employeeLookup.GetLocationSiteIdByEmployeeSerialAsync(result.EmployeeId).ConfigureAwait(true);
+                _config,
-                _config.ApplyLocationSiteIdFromAuth(siteId);
+                _employeeLookup,
-            }
+                _backendApi).ConfigureAwait(true);
-            catch
+
-            {
+            FileLogger.Info(
-                // HRMS lookup optional; login still succeeds.
+                "ClientLogin",
-            }
+                $"Admin login succeeded. EmployeeId={result.EmployeeId}, AdminCardId saved, SiteId={_config.GetSiteId()}");
 
             // Persist who logged in (for audit / reporting).
             await _adminAudit.RecordLoginAsync(user, result.EmployeeId).ConfigureAwait(false);

ViewModels/AdminSettingsAuthViewModel.cs

@@ -11,6 +11,7 @@ public partial class AdminSettingsAuthViewModel : ObservableObject
     private readonly INavigationService _navigation;
     private readonly IConfigService _config;
     private readonly IEmployeeLookupService _employeeLookup;
+    private readonly ICanteenBackendApiClient? _backendApi;
 
     [ObservableProperty]
     private string _username = string.Empty;
@@ -33,13 +34,15 @@ public partial class AdminSettingsAuthViewModel : ObservableObject
         AppSession session,
         INavigationService navigation,
         IConfigService config,
-        IEmployeeLookupService employeeLookup)
+        IEmployeeLookupService employeeLookup,
+        ICanteenBackendApiClient? backendApi = null)
     {
         _authService = authService;
         _session = session;
         _navigation = navigation;
         _config = config;
         _employeeLookup = employeeLookup;
+        _backendApi = backendApi;
 
         RememberCredentials = _config.GetRememberAdminCredentials();
         if (RememberCredentials)
@@ -90,15 +93,11 @@ public partial class AdminSettingsAuthViewModel : ObservableObject
             // Refresh session details (who authenticated for Settings).
             _session.SetAdminAuthenticated(user, result.EmployeeId);
 
-            try
+            await AdminLoginHelper.ApplyAdminLoginDefaultsAsync(
-            {
+                result.EmployeeId,
-                var siteId = await _employeeLookup.GetLocationSiteIdByEmployeeSerialAsync(result.EmployeeId).ConfigureAwait(true);
+                _config,
-                _config.ApplyLocationSiteIdFromAuth(siteId);
+                _employeeLookup,
-            }
+                _backendApi).ConfigureAwait(true);
-            catch
-            {
-                // HRMS lookup optional; auth still succeeds.
-            }
 
             // Persist credentials only if user opted in.
             _config.SetRememberAdminCredentials(RememberCredentials);

ViewModels/MealSchedulesViewModel.cs

@@ -246,6 +246,7 @@ using CommunityToolkit.Mvvm.Input;
 using MySqlConnector;
 using UtopiaCanteenSystem.Models;
 using UtopiaCanteenSystem.Services;
+using UtopiaCanteenSystem.Services.Logging;
 
 namespace UtopiaCanteenSystem.ViewModels;
 
@@ -289,6 +290,7 @@ public partial class MealSchedulesViewModel : ObservableObject
         _navigation = navigation;
         _configService = configService;
         _currentSiteId = (_configService.GetSiteId() ?? string.Empty).Trim();
+        FileLogger.Info("MealSchedules", "Meal Schedules view opened; loading schedules from backend.");
         _ = LoadSchedulesAsync();
     }
 
@@ -352,12 +354,13 @@ public partial class MealSchedulesViewModel : ObservableObject
         catch (Exception ex)
         {
             IsError = true;
+            FileLogger.Error("MealSchedules", "Could not load schedules from backend.", ex);
 
             var msg = ex is MySqlException mysql
                 ? $"{mysql.Message}{Environment.NewLine}{Environment.NewLine}{mysql.StackTrace}"
                 : $"{ex.Message}{Environment.NewLine}{Environment.NewLine}{ex.StackTrace}";
 
-            Message = "Could not load schedules.";
+            Message = "Could not load schedules from backend.";
             MessageBox.Show(msg, "Meal Schedules – Load Error", MessageBoxButton.OK, MessageBoxImage.Error);
         }
         finally

ViewModels/ScannerDashboardViewModel.cs

@@ -12,6 +12,7 @@ using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using UtopiaCanteenSystem.Models;
 using UtopiaCanteenSystem.Services;
+using UtopiaCanteenSystem.Services.Logging;
 
 namespace UtopiaCanteenSystem.ViewModels;
 
@@ -215,22 +216,7 @@ public partial class ScannerDashboardViewModel : ObservableObject
         _clockTimer.Tick += (_, _) => CurrentTime = DateTime.Now.ToString("MM/dd/yyyy, hh:mm:ss tt");
         _clockTimer.Start();
 
-        // Load initial site from config.
+        RefreshSiteFromConfig();
-      var siteId = _configService.GetSiteId();
-      if (!string.IsNullOrWhiteSpace(siteId))
-        {
-            // Extract digits from legacy format "SITE : X"or use value directly if already numeric
-          if (siteId.StartsWith("SITE : ", StringComparison.OrdinalIgnoreCase))
-            {
-              var num = siteId.Substring("SITE : ".Length).Trim();
-              if (num.Length > 0 && num.All(char.IsDigit))
-                    SiteNumber = num;
-            }
-            else if (siteId.All(char.IsDigit))
-            {
-                SiteNumber = siteId;
-            }
-        }
 
         RefreshScannerStatus();
         _ = RefreshDashboardAsync();
@@ -361,6 +347,13 @@ public partial class ScannerDashboardViewModel : ObservableObject
         return localDate.ToString("MMM d");
     }
 
+    /// <summary>Loads SITE header from config (set on admin login).</summary>
+    public void RefreshSiteFromConfig()
+    {
+        SiteNumber = AdminLoginHelper.ExtractSiteDigits(_configService.GetSiteId());
+        OnPropertyChanged(nameof(CurrentSiteDisplay));
+    }
+
     partial void OnSiteNumberChanged(string value)
     {
         // Numeric only: filter to digits so display stays valid.
@@ -578,9 +571,11 @@ public partial class ScannerDashboardViewModel : ObservableObject
             if (string.IsNullOrWhiteSpace(cardId))
                 return;
 
+            FileLogger.Info("ClientScan", $"Scan started. CardId={LogMasking.MaskCardId(cardId)}");
             var result = _rfidService.ProcessScanDetailed(cardId);
             IsSuccess = result.Success;
             Message = result.Message;
+            FileLogger.Info("ClientScan", $"Scan UI message. Success={result.Success}, Message={result.Message}");
 
             // Check if this is a site mismatch error
             if (!result.Success && result.Message.Contains("not allowed to scan here"))
@@ -933,10 +928,14 @@ public partial class ScannerDashboardViewModel : ObservableObject
     private static string BuildCsvFromScanRecords(IReadOnlyList<ScanRecord> records)
     {
         var sb = new StringBuilder();
-        sb.AppendLine("Id,CardId,ScanTime,IsSynced,SiteId,DeviceId,IpAddress,EmployeeId,EmployeeName,Department,Meal,Price");
+        sb.AppendLine("Id,CardId,ScanTime,IsSynced,SiteId,DeviceId,IpAddress,EmployeeId,EmployeeName,Department,Meal Session,Meal,Price");
         foreach (var r in records)
         {
             var localScanTime = r.ScanTime.ToLocalTime();
+            var mealSession = r.MealLabel ?? string.Empty;
+            var meal = !string.IsNullOrWhiteSpace(r.MealItems)
+                ? r.MealItems
+                : mealSession;
             sb.Append(r.Id);
             sb.Append(',');
             sb.Append(ToExcelText(r.CardId));
@@ -957,7 +956,9 @@ public partial class ScannerDashboardViewModel : ObservableObject
             sb.Append(',');
             sb.Append(EscapeCsv(r.Department ?? string.Empty));
             sb.Append(',');
-            sb.Append(EscapeCsv(r.MealItems ?? string.Empty));
+            sb.Append(EscapeCsv(mealSession));
+            sb.Append(',');
+            sb.Append(EscapeCsv(meal));
             sb.Append(',');
             sb.Append(r.TotalPrice.ToString("0.##", CultureInfo.InvariantCulture));
             sb.AppendLine();
@@ -1052,4 +1053,3 @@ public partial class ScannerDashboardViewModel : ObservableObject
         _debounceTimer.Stop();
     }
 }
-

ViewModels/SettingsViewModel.cs

@@ -1,18 +1,19 @@
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
+using UtopiaCanteenSystem.Models;
 using UtopiaCanteenSystem.Services;
 
 namespace UtopiaCanteenSystem.ViewModels;
 
 /// <summary>
-/// ViewModel for SettingsView: editable API endpoint (UIND sync URL), save, load from config.
+/// Settings UI (frontend): persists local kiosk config; cache/production jobs call backend APIs only.
 /// </summary>
 public partial class SettingsViewModel : ObservableObject
 {
     private readonly IConfigService _configService;
     private readonly INavigationService _navigation;
     private readonly IAdminAuditService _adminAudit;
-    private readonly ISyncService _syncService;
+    private readonly ICanteenBackendApiClient _backendApi;
 
     [ObservableProperty]
     private string _syncApiEndpoint = string.Empty;
@@ -44,9 +45,40 @@ public partial class SettingsViewModel : ObservableObject
     [ObservableProperty]
     private bool _isPosting;
 
+    [ObservableProperty]
+    private bool _isSyncingCache;
 
-    public bool CanPostNow => !IsPosting;
+    [ObservableProperty]
-    public string PostButtonText => IsPosting ? "Posting..." : "Post Data";
+    private string _lastEmployeeRfidCacheSyncDisplay = "Never";
+
+    [ObservableProperty]
+    private string _lastMealMenuCacheSyncDisplay = "Never";
+
+    [ObservableProperty]
+    private string _selectedAppMode = "Server";
+
+    [ObservableProperty]
+    private string _backendBaseUrl = string.Empty;
+
+    [ObservableProperty]
+    private string _localServerListenUrls = "http://0.0.0.0:5000";
+
+    public IReadOnlyList<string> AppModeOptions { get; } = new[] { "Server", "Client" };
+
+    public bool IsCentralServerMode => string.Equals(SelectedAppMode, "Server", StringComparison.OrdinalIgnoreCase);
+
+    public string EffectiveBackendUrlDisplay =>
+        IsCentralServerMode
+            ? _configService.GetBackendBaseUrl()
+            : (BackendBaseUrl?.Trim() ?? string.Empty);
+
+    public bool HasBackendUrl => !string.IsNullOrWhiteSpace(_configService.GetBackendBaseUrl());
+
+    public bool CanPostNow => !IsPosting && HasBackendUrl;
+    public string PostButtonText => IsPosting ? "Posting..." : "Post Pending Orders";
+
+    public bool CanSyncCacheNow => !IsSyncingCache && HasBackendUrl;
+    public string SyncCacheButtonText => IsSyncingCache ? "Syncing cache..." : "Sync Now";
 
     partial void OnIsPostingChanged(bool value)
     {
@@ -54,20 +86,41 @@ public partial class SettingsViewModel : ObservableObject
         OnPropertyChanged(nameof(CanPostNow));
     }
 
+    partial void OnIsSyncingCacheChanged(bool value)
+    {
+        OnPropertyChanged(nameof(SyncCacheButtonText));
+        OnPropertyChanged(nameof(CanSyncCacheNow));
+    }
+
+    partial void OnSelectedAppModeChanged(string value)
+    {
+        OnPropertyChanged(nameof(IsCentralServerMode));
+        OnPropertyChanged(nameof(EffectiveBackendUrlDisplay));
+        OnPropertyChanged(nameof(CanPostNow));
+        OnPropertyChanged(nameof(CanSyncCacheNow));
+    }
+
+    partial void OnBackendBaseUrlChanged(string value)
+    {
+        OnPropertyChanged(nameof(HasBackendUrl));
+        OnPropertyChanged(nameof(CanPostNow));
+        OnPropertyChanged(nameof(CanSyncCacheNow));
+    }
+
     public SettingsViewModel(
         IConfigService configService,
         INavigationService navigation,
         IAdminAuditService adminAudit,
-        ISyncService syncService)
+        ICanteenBackendApiClient backendApi)
     {
         _configService = configService;
         _navigation = navigation;
         _adminAudit = adminAudit;
-        _syncService = syncService;
+        _backendApi = backendApi;
         LoadFromConfig();
+        _ = RefreshCacheSyncTimestampsAsync();
     }
 
-    /// <summary>Loads config from service.</summary>
     public void LoadFromConfig()
     {
         SyncApiEndpoint = _configService.GetSyncApiEndpoint();
@@ -76,12 +129,37 @@ public partial class SettingsViewModel : ObservableObject
         ScanIntervalMinutes = _configService.GetScanIntervalMinutes().ToString();
         ScanIntervalSeconds = _configService.GetScanIntervalSeconds().ToString();
 
-        // Always prefer the latest admin login from the database.
+        AdminCardId = AdminLoginHelper.ResolveAdminCardIdForDisplay(_configService, adminAudit: _adminAudit);
-        var last = _adminAudit.GetLastLogin();
+
-        if (last != null && !string.IsNullOrWhiteSpace(last.EmployeeId))
+        SelectedAppMode = _configService.GetAppMode() == AppMode.Client ? "Client" : "Server";
-            AdminCardId = last.EmployeeId;
+        BackendBaseUrl = string.IsNullOrWhiteSpace(_configService.GetCentralServerBaseUrl())
-        else
+            ? _configService.GetBackendBaseUrl()
-            AdminCardId = "ADMIN";
+            : _configService.GetCentralServerBaseUrl();
+        LocalServerListenUrls = _configService.GetLocalServerListenUrls();
+        OnPropertyChanged(nameof(EffectiveBackendUrlDisplay));
+        OnPropertyChanged(nameof(HasBackendUrl));
+    }
+
+    public async Task RefreshCacheSyncTimestampsAsync()
+    {
+        if (IsCentralServerMode)
+        {
+            LastEmployeeRfidCacheSyncDisplay = FormatSyncTime(_configService.GetLastEmployeeRfidCacheSyncUtc());
+            LastMealMenuCacheSyncDisplay = FormatSyncTime(_configService.GetLastMealMenuCacheSyncUtc());
+            return;
+        }
+
+        var status = await _backendApi.GetCacheStatusAsync().ConfigureAwait(true);
+        if (status != null)
+        {
+            LastEmployeeRfidCacheSyncDisplay = FormatSyncTime(status.LastEmployeeRfidCacheSyncUtc);
+            LastMealMenuCacheSyncDisplay = FormatSyncTime(status.LastMealMenuCacheSyncUtc);
+        }
+    }
+
+    public void RefreshCacheSyncTimestamps()
+    {
+        _ = RefreshCacheSyncTimestampsAsync();
     }
 
     [RelayCommand]
@@ -124,15 +202,32 @@ public partial class SettingsViewModel : ObservableObject
             return;
         }
 
+        if (string.Equals(SelectedAppMode, "Client", StringComparison.OrdinalIgnoreCase) &&
+            string.IsNullOrWhiteSpace(BackendBaseUrl?.Trim()))
+        {
+            SaveMessage = "Client mode requires Backend base URL (e.g. http://192.168.1.10:5000).";
+            IsError = true;
+            IsSaving = false;
+            return;
+        }
+
+        _configService.SetAppMode(string.Equals(SelectedAppMode, "Client", StringComparison.OrdinalIgnoreCase)
+            ? AppMode.Client
+            : AppMode.Server);
+        _configService.SetCentralServerBaseUrl(BackendBaseUrl?.Trim() ?? string.Empty);
+        _configService.SetLocalServerListenUrls(LocalServerListenUrls?.Trim() ?? string.Empty);
+
         _configService.SetSyncApiEndpoint(SyncApiEndpoint?.Trim() ?? string.Empty);
         _configService.SetScanIntervalDays(days);
         _configService.SetScanIntervalHours(hours);
         _configService.SetScanIntervalMinutes(minutes);
         _configService.SetScanIntervalSeconds(seconds);
         _configService.SetAdminCardId(AdminCardId?.Trim() ?? string.Empty);
-        SaveMessage = "Settings saved.";
+        SaveMessage = "Settings saved. Restart the app after changing App mode or listen URLs.";
         IsError = false;
         IsSaving = false;
+        OnPropertyChanged(nameof(EffectiveBackendUrlDisplay));
+        OnPropertyChanged(nameof(HasBackendUrl));
     }
 
     [RelayCommand]
@@ -141,13 +236,58 @@ public partial class SettingsViewModel : ObservableObject
         _navigation.NavigateBackFromSettings(GetDashboardTimeout());
     }
 
-    /// <summary>Opens Meal Schedules admin screen (Phase 2.5).</summary>
     [RelayCommand]
     private void OpenMealSchedules()
     {
         _navigation.NavigateToMealSchedules();
     }
 
+    [RelayCommand]
+    private async Task SyncEmployeeAndMenuCacheNow()
+    {
+        if (IsSyncingCache)
+            return;
+
+        SaveMessage = "Syncing cache...";
+        IsError = false;
+        IsSyncingCache = true;
+
+        try
+        {
+            if (string.IsNullOrWhiteSpace(_configService.GetBackendBaseUrl()))
+            {
+                SaveMessage = "Backend URL is not configured.";
+                IsError = true;
+                return;
+            }
+
+            if (!await _backendApi.HealthCheckAsync().ConfigureAwait(true))
+            {
+                SaveMessage = "Cannot reach backend. Ensure the central server app is running and API is listening.";
+                IsError = true;
+                return;
+            }
+
+            var result = await _backendApi.SyncCacheNowAsync().ConfigureAwait(true);
+            await RefreshCacheSyncTimestampsAsync().ConfigureAwait(true);
+
+            SaveMessage = result.Message;
+            IsError = !result.Success;
+            if (!string.IsNullOrWhiteSpace(result.Details) && result.Success)
+                SaveMessage += " " + result.Details;
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "SettingsViewModel.SyncEmployeeAndMenuCacheNow");
+            SaveMessage = "Cache sync failed: " + ex.Message;
+            IsError = true;
+        }
+        finally
+        {
+            IsSyncingCache = false;
+        }
+    }
+
     [RelayCommand]
     private async Task PostDataNow()
     {
@@ -160,21 +300,30 @@ public partial class SettingsViewModel : ObservableObject
 
         try
         {
-            // If not configured, do not attempt sync.
+            if (string.IsNullOrWhiteSpace(_configService.GetBackendBaseUrl()))
-            if (string.IsNullOrWhiteSpace(_configService.GetMySqlConnectionString()))
             {
-                SaveMessage = "MySQL connection string not configured.";
+                SaveMessage = "Backend URL is not configured.";
                 IsError = true;
                 return;
             }
 
-            await _syncService.SyncNowAsync().ConfigureAwait(false);
+            if (!await _backendApi.HealthCheckAsync().ConfigureAwait(true))
-            SaveMessage = "Posted data to production.";
-            IsError = false;
-        }
-        catch
             {
-            SaveMessage = "Failed to post data to production.";
+                SaveMessage = "Cannot reach backend. Ensure the central server app is running.";
+                IsError = true;
+                return;
+            }
+
+            var result = await _backendApi.SyncOrdersNowAsync().ConfigureAwait(true);
+            SaveMessage = result.Message;
+            IsError = !result.Success;
+            if (!string.IsNullOrWhiteSpace(result.Details) && result.Success)
+                SaveMessage += " " + result.Details;
+        }
+        catch (Exception ex)
+        {
+            Logger.Log(ex, "SettingsViewModel.PostDataNow");
+            SaveMessage = "Failed to post pending orders: " + ex.Message;
             IsError = true;
         }
         finally
@@ -183,5 +332,12 @@ public partial class SettingsViewModel : ObservableObject
         }
     }
 
+    private static string FormatSyncTime(DateTime? utc)
+    {
+        if (utc == null)
+            return "Never";
+        return utc.Value.ToLocalTime().ToString("MM/dd/yyyy, hh:mm:ss tt");
+    }
+
     private TimeSpan GetDashboardTimeout() => _configService.GetScanInterval();
 }

Views/SettingsView.xaml

@@ -2,6 +2,7 @@
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
     <UserControl.Resources>
+        <BooleanToVisibilityConverter x:Key="BoolToVis" />
         <SolidColorBrush x:Key="AppBackground" Color="#F0F2F5"/>
         <SolidColorBrush x:Key="CardBackground" Color="#FFFFFF"/>
         <SolidColorBrush x:Key="PrimaryText" Color="#2D3748"/>
@@ -273,46 +274,82 @@
                                            Foreground="{StaticResource MutedText}"
                                            Margin="0,0,0,20" />
 
-                                <!--<TextBlock Text="Sync API Endpoint (UIND)" FontSize="16" Foreground="{StaticResource PrimaryText}" FontWeight="SemiBold" />
+                                <TextBlock Text="Application mode" FontSize="16" Foreground="{StaticResource PrimaryText}" FontWeight="SemiBold" />
-                                <TextBox Text="{Binding SyncApiEndpoint, UpdateSourceTrigger=PropertyChanged}"
+                                <TextBlock Text="Server: this PC hosts SQLite, sync jobs, and the local HTTP API for scanners. Client: this PC only sends scans to the central server."
-                                         Style="{StaticResource ModernTextBoxStyle}" Margin="0,8,0,8" />
-                                <TextBlock Text="Endpoint used to sync scan records."
                                            FontSize="14"
                                            Foreground="{StaticResource MutedText}"
-                                           Margin="0,0,0,20" />-->
+                                           Margin="0,4,0,8" />
-                                <TextBlock Text="Sync Data To (UIND)"
+                                <ComboBox ItemsSource="{Binding AppModeOptions}"
+                                          SelectedItem="{Binding SelectedAppMode, Mode=TwoWay}"
+                                          MinHeight="44"
                                           FontSize="16"
-           Foreground="{StaticResource PrimaryText}"
+                                          Margin="0,0,0,12"
-           FontWeight="SemiBold" />
+                                          Padding="12,8"/>
 
-                                <Grid Margin="0,8,0,8">
+                                <TextBlock Text="Backend base URL" FontSize="16" Foreground="{StaticResource PrimaryText}" FontWeight="SemiBold" />
+                                <TextBox Text="{Binding BackendBaseUrl, UpdateSourceTrigger=PropertyChanged}"
+                                         Style="{StaticResource ModernTextBoxStyle}" Margin="0,8,0,4" />
+                                <TextBlock Text="Client: central server IP (e.g. http://192.168.1.10:5000). Server: leave blank to use http://localhost:5000 from listen URL below."
+                                           FontSize="14"
+                                           Foreground="{StaticResource MutedText}"
+                                           Margin="0,0,0,4" />
+                                <TextBlock Text="{Binding EffectiveBackendUrlDisplay, StringFormat=API calls use: {0}}"
+                                           FontSize="14"
+                                           Foreground="{StaticResource MutedText}"
+                                           Margin="0,0,0,12" />
+
+                                <TextBlock Text="Local API listen URL(s) (central server only)" FontSize="16" Foreground="{StaticResource PrimaryText}" FontWeight="SemiBold" />
+                                <TextBox Text="{Binding LocalServerListenUrls, UpdateSourceTrigger=PropertyChanged}"
+                                         Style="{StaticResource ModernTextBoxStyle}" Margin="0,8,0,4" />
+                                <TextBlock Text="Example: http://0.0.0.0:5000 — Kestrel bind address on the server PC."
+                                           FontSize="14"
+                                           Foreground="{StaticResource MutedText}"
+                                           Margin="0,0,0,20" />
+
+                                <TextBlock Text="Backend jobs (calls central API — same on server and client)" FontSize="16" Foreground="{StaticResource PrimaryText}" FontWeight="SemiBold" Margin="0,0,0,8" />
+
+                                <TextBlock Text="Download employee RFID tags, meal schedules, and menu data to central SQLite (HRMS → backend)."
+                                           FontSize="14"
+                                           Foreground="{StaticResource MutedText}"
+                                           Margin="0,0,0,8" />
+
+                                <Button Content="{Binding SyncCacheButtonText}"
+                                        Command="{Binding SyncEmployeeAndMenuCacheNowCommand}"
+                                        Style="{StaticResource PrimaryButtonStyle}"
+                                        MinWidth="280"
+                                        HorizontalAlignment="Left"
+                                        Margin="0,0,0,8"
+                                        IsEnabled="{Binding CanSyncCacheNow}" />
+
+                                <TextBlock Text="{Binding LastEmployeeRfidCacheSyncDisplay, StringFormat=Last employee RFID cache sync: {0}}"
+                                           FontSize="14"
+                                           Foreground="{StaticResource MutedText}"
+                                           Margin="0,0,0,4" />
+                                <TextBlock Text="{Binding LastMealMenuCacheSyncDisplay, StringFormat=Last meal/menu cache sync: {0}}"
+                                           FontSize="14"
+                                           Foreground="{StaticResource MutedText}"
+                                           Margin="0,0,0,12" />
+
+                                <Grid Margin="0,0,0,8">
                                     <Grid.ColumnDefinitions>
                                         <ColumnDefinition Width="*" />
                                         <ColumnDefinition Width="16" />
                                         <ColumnDefinition Width="Auto" />
                                     </Grid.ColumnDefinitions>
-
                                     <TextBlock Grid.Column="0"
-                                               Text="Post data to production"
+                                               Text="Post pending orders to production (UIND)"
                                                FontSize="18"
                                                Foreground="{StaticResource PrimaryText}"
                                                VerticalAlignment="Center"
                                                Margin="4,0,0,0" />
-
-                                    <!-- Post button right next to textbox -->
                                     <Button Grid.Column="2"
                                             Content="{Binding PostButtonText}"
                                             Command="{Binding PostDataNowCommand}"
                                             Style="{StaticResource PrimaryButtonStyle}"
-            MinWidth="150"
+                                            MinWidth="200"
                                             IsEnabled="{Binding CanPostNow}" />
                                 </Grid>
 
-                                <TextBlock Text=""
-                                           FontSize="14"
-                                           Foreground="{StaticResource MutedText}"
-                                           Margin="0,0,0,20" />
-
                                 <!-- Message area -->
                                 <Border Margin="0,0,0,20" Padding="16" CornerRadius="8">
                                     <Border.Style>
@@ -396,7 +433,8 @@
                                                 Command="{Binding OpenMealSchedulesCommand}"
                                                 Style="{StaticResource OutlineButtonStyle}"
                                                 MinWidth="120"
-                                                Margin="0,0,16,0" />
+                                                Margin="0,0,16,0"
+                                                Visibility="{Binding IsCentralServerMode, Converter={StaticResource BoolToVis}}" />
                                         <Button Content="Back"
                                                 Command="{Binding BackCommand}"
                                                 Style="{StaticResource OutlineButtonStyle}"

Views/SettingsView.xaml.cs

@@ -18,5 +18,6 @@ public partial class SettingsView : UserControl
     {
         InitializeComponent();
         DataContext = viewModel;
+        Loaded += (_, _) => viewModel.RefreshCacheSyncTimestamps();
     }
 }

scripts/clean-build.ps1

@@ -0,0 +1,40 @@
+$ErrorActionPreference = "Continue"
+
+Write-Host "Stopping .NET build servers..."
+dotnet build-server shutdown
+
+Write-Host "Killing running app/dotnet processes..."
+taskkill /F /IM dotnet.exe 2>$null
+taskkill /F /IM UtopiaCanteen.Client.exe 2>$null
+taskkill /F /IM UtopiaCanteen.BackendService.exe 2>$null
+taskkill /F /IM UtopiaCanteenSystem.exe 2>$null
+
+$root = Split-Path -Parent $PSScriptRoot
+Set-Location $root
+
+$me = "$env:USERDOMAIN\$env:USERNAME"
+
+$targets = @(
+    "obj",
+    "bin",
+    "UtopiaCanteen.BackendService\obj",
+    "UtopiaCanteen.BackendService\bin",
+    "UtopiaCanteen.Client\obj",
+    "UtopiaCanteen.Client\bin",
+    "UtopiaCanteen.Backend\obj",
+    "UtopiaCanteen.Backend\bin",
+    "UtopiaCanteen.Shared\obj",
+    "UtopiaCanteen.Shared\bin"
+)
+
+foreach ($t in $targets) {
+    if (Test-Path $t) {
+        Write-Host "Taking ownership and removing: $t"
+        takeown /F $t /R /D Y | Out-Null
+        icacls $t /grant "${me}:(OI)(CI)F" /T /C | Out-Null
+        attrib -R $t /S /D
+        Remove-Item -LiteralPath $t -Recurse -Force -ErrorAction SilentlyContinue
+    }
+}
+
+Write-Host "Clean complete."

scripts/install-backend-service.ps1

@@ -0,0 +1,83 @@
+# Install or reinstall the Utopia Canteen backend as a Windows Service (requires Administrator).
+param(
+    [string]$InstallPath = "C:\UtopiaCanteenBackend",
+    [string]$ServiceName = "UtopiaCanteenBackend",
+    [string]$DisplayName = "Utopia Canteen Backend",
+    [ValidateSet("Debug", "Release")]
+    [string]$Configuration = "Release",
+    [switch]$SkipPublish,
+    [switch]$AddUrlAcl,
+    [string]$UrlAclUser = "Everyone"
+)
+
+$ErrorActionPreference = "Stop"
+
+function Test-Administrator {
+    $current = [Security.Principal.WindowsIdentity]::GetCurrent()
+    $principal = New-Object Security.Principal.WindowsPrincipal($current)
+    return $principal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)
+}
+
+if (-not (Test-Administrator)) {
+    Write-Error "Run this script in an elevated PowerShell (Run as administrator)."
+    exit 1
+}
+
+$ScriptDir = $PSScriptRoot
+if (-not $SkipPublish) {
+    & (Join-Path $ScriptDir "publish-backend.ps1") -OutputPath $InstallPath -Configuration $Configuration
+}
+
+$ExePath = Join-Path $InstallPath "UtopiaCanteen.BackendService.exe"
+if (-not (Test-Path $ExePath)) {
+    throw "Executable not found: $ExePath. Run publish-backend.ps1 first."
+}
+
+# HttpListener on http://+:5000/ often needs a URL reservation.
+if ($AddUrlAcl) {
+    Write-Host "Adding URL ACL for http://+:5000/ (user: $UrlAclUser)"
+    netsh http add urlacl url=http://+:5000/ user=$UrlAclUser 2>$null
+    if ($LASTEXITCODE -ne 0) {
+        Write-Warning "urlacl may already exist or failed (exit $LASTEXITCODE). Continue if the service binds OK."
+    }
+}
+
+$existing = Get-Service -Name $ServiceName -ErrorAction SilentlyContinue
+if ($existing) {
+    Write-Host "Stopping and removing existing service: $ServiceName"
+    if ($existing.Status -eq "Running") {
+        Stop-Service -Name $ServiceName -Force -ErrorAction SilentlyContinue
+        Start-Sleep -Seconds 2
+    }
+    sc.exe delete $ServiceName | Out-Null
+    Start-Sleep -Seconds 2
+}
+
+$binPath = "`"$ExePath`""
+Write-Host "Creating service $ServiceName -> $ExePath"
+sc.exe create $ServiceName binPath= $binPath start= auto DisplayName= $DisplayName
+if ($LASTEXITCODE -ne 0) {
+    throw "sc create failed with exit code $LASTEXITCODE"
+}
+
+sc.exe description $ServiceName "Central canteen API, SQLite, and HRMS/UIND sync for RFID scanners."
+sc.exe failure $ServiceName reset= 86400 actions= restart/60000/restart/60000/restart/60000
+
+Write-Host "Starting service..."
+sc.exe start $ServiceName
+if ($LASTEXITCODE -ne 0) {
+    Write-Warning "sc start returned $LASTEXITCODE. Check Event Viewer and appsettings.json."
+} else {
+    Write-Host "Service started. Health check: http://localhost:5000/api/health"
+}
+
+Write-Host @"
+
+Installed:
+  Path:    $InstallPath
+  Service: $ServiceName (auto-start)
+  Data:    %LocalAppData%\UtopiaCanteenBackend\
+
+Firewall: allow inbound TCP 5000 on this PC for scanner clients.
+
+"@

scripts/publish-backend-selfcontained.ps1

@@ -0,0 +1,20 @@
+$ErrorActionPreference = "Stop"
+
+$ProjectPath = ".\UtopiaCanteen.BackendService\UtopiaCanteen.BackendService.csproj"
+$OutputPath = "C:\Users\Public\UtopiaCanteenBackend"
+
+Write-Host "Cleaning old backend publish folder..."
+if (Test-Path $OutputPath) {
+    Remove-Item $OutputPath -Recurse -Force
+}
+
+Write-Host "Publishing backend as self-contained..."
+dotnet publish $ProjectPath `
+    -c Release `
+    -r win-x64 `
+    --self-contained true `
+    -p:PublishSingleFile=false `
+    -o $OutputPath
+
+Write-Host "Backend self-contained publish completed:"
+Write-Host $OutputPath

scripts/publish-backend.ps1

@@ -0,0 +1,57 @@
+# Publish UtopiaCanteen.BackendService to a folder (default C:\UtopiaCanteenBackend).
+# Default: self-contained win-x64 (no .NET runtime required on target PC).
+param(
+    [string]$OutputPath = "C:\UtopiaCanteenBackend",
+    [ValidateSet("Debug", "Release")]
+    [string]$Configuration = "Release",
+    [string]$Runtime = "win-x64",
+    [switch]$FrameworkDependent,
+    [switch]$SelfContained
+)
+
+$ErrorActionPreference = "Stop"
+$Root = Split-Path -Parent $PSScriptRoot
+$Project = Join-Path $Root "UtopiaCanteen.BackendService\UtopiaCanteen.BackendService.csproj"
+
+if (-not (Test-Path $Project)) {
+    throw "Project not found: $Project"
+}
+
+# Self-contained unless -FrameworkDependent is passed.
+$isSelfContained = -not $FrameworkDependent
+if ($SelfContained) {
+    $isSelfContained = $true
+}
+
+$publishArgs = @(
+    "publish", $Project,
+    "-c", $Configuration,
+    "-o", $OutputPath
+)
+
+if ($isSelfContained) {
+    $publishArgs += @("-r", $Runtime, "--self-contained", "true")
+    Write-Host "Publishing backend ($Configuration, self-contained $Runtime) -> $OutputPath"
+} else {
+    $publishArgs += @("--self-contained", "false")
+    Write-Host "Publishing backend ($Configuration, framework-dependent) -> $OutputPath"
+    Write-Host "Target PC must have .NET 8 Desktop Runtime installed."
+}
+
+dotnet @publishArgs
+
+if ($LASTEXITCODE -ne 0) {
+    throw "dotnet publish failed with exit code $LASTEXITCODE"
+}
+
+$appsettings = Join-Path $OutputPath "appsettings.json"
+if (Test-Path $appsettings) {
+    Write-Host "Edit connection strings in: $appsettings"
+}
+
+Write-Host @"
+Done. Executable: $(Join-Path $OutputPath 'UtopiaCanteen.BackendService.exe')
+
+Deploy: copy the entire folder '$OutputPath' to the server PC.
+$(if ($isSelfContained) { "Self-contained: .NET runtime is included; no separate install needed." } else { "Framework-dependent: install .NET 8 Runtime on the server." })
+"@

scripts/publish-client-selfcontained.ps1

@@ -0,0 +1,20 @@
+$ErrorActionPreference = "Stop"
+
+$ProjectPath = ".\UtopiaCanteen.Client\UtopiaCanteen.Client.csproj"
+$OutputPath = "C:\Users\Public\UtopiaCanteenClient"
+
+Write-Host "Cleaning old client publish folder..."
+if (Test-Path $OutputPath) {
+    Remove-Item $OutputPath -Recurse -Force
+}
+
+Write-Host "Publishing client as self-contained..."
+dotnet publish $ProjectPath `
+    -c Release `
+    -r win-x64 `
+    --self-contained true `
+    -p:PublishSingleFile=false `
+    -o $OutputPath
+
+Write-Host "Client self-contained publish completed:"
+Write-Host $OutputPath

scripts/publish-client.ps1

@@ -0,0 +1,54 @@
+# Publish UtopiaCanteen.Client (WPF scanner) to a folder (default C:\UtopiaCanteenClient).
+# Default: self-contained win-x64 (no .NET runtime required on target PC).
+param(
+    [string]$OutputPath = "C:\UtopiaCanteenClient",
+    [ValidateSet("Debug", "Release")]
+    [string]$Configuration = "Release",
+    [string]$Runtime = "win-x64",
+    [switch]$FrameworkDependent,
+    [switch]$SelfContained
+)
+
+$ErrorActionPreference = "Stop"
+$Root = Split-Path -Parent $PSScriptRoot
+$Project = Join-Path $Root "UtopiaCanteen.Client\UtopiaCanteen.Client.csproj"
+
+if (-not (Test-Path $Project)) {
+    throw "Project not found: $Project"
+}
+
+$isSelfContained = -not $FrameworkDependent
+if ($SelfContained) {
+    $isSelfContained = $true
+}
+
+$publishArgs = @(
+    "publish", $Project,
+    "-c", $Configuration,
+    "-o", $OutputPath
+)
+
+if ($isSelfContained) {
+    $publishArgs += @("-r", $Runtime, "--self-contained", "true")
+    Write-Host "Publishing client ($Configuration, self-contained $Runtime) -> $OutputPath"
+} else {
+    $publishArgs += @("--self-contained", "false")
+    Write-Host "Publishing client ($Configuration, framework-dependent) -> $OutputPath"
+    Write-Host "Target PC must have .NET 8 Desktop Runtime installed."
+}
+
+dotnet @publishArgs
+
+if ($LASTEXITCODE -ne 0) {
+    throw "dotnet publish failed with exit code $LASTEXITCODE"
+}
+
+Write-Host @"
+Done. Run: $(Join-Path $OutputPath 'UtopiaCanteen.Client.exe')
+
+Deploy: copy the entire folder '$OutputPath' to each scanner PC (or your file share).
+$(if ($isSelfContained) { "Self-contained: .NET runtime is included; no separate install needed." } else { "Framework-dependent: install .NET 8 Desktop Runtime on each PC." })
+
+First run: open Settings and set Backend base URL (e.g. http://192.168.1.10:5000).
+Config file: %LocalAppData%\UtopiaCanteenClient\appsettings.json
+"@