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.

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-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