Inbox: Export CSV button; graceful partial failure on the All channel

Export downloads the current view - channel, tab and search respected,
fetched unpaged - as UTF-8 CSV (BOM for Excel) with both sources'
columns: name, contact, position, channel, source, received, status,
city, notice period, ATS score, assigned job.

All channel resilience: when exactly one source fails, the healthy
list stays with a one-line notice naming the gap; the full error state
now renders only when there are no rows at all (cached rows beat a
scary banner over a working list).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/screens/Inbox.jsx

@@ -1044,6 +1044,63 @@ export default function Inbox() {
     markDuplicate.mutate({ id: item.id, isDuplicate: !item.duplicate, kind: item.kind })
   }
 
+  const [exporting, setExporting] = useState(false)
+
+  /** CSV of the current view — channel, tab and search respected, unpaged. */
+  async function exportCsv() {
+    if (exporting) return
+    setExporting(true)
+    try {
+      const search = q.trim() ? { search: q.trim() } : {}
+      const [emailRes, formRes] = await Promise.all([
+        !isForms
+          ? fetchApplications({ ...tabFilter, ...search })
+          : Promise.resolve({ rows: [] }),
+        isForms || isAllChannel
+          ? fetchFormApplications({
+              sheet: isAllChannel ? undefined : (formSheet || undefined),
+              ...formTabFilter,
+              ...search,
+            })
+          : Promise.resolve({ rows: [] }),
+      ])
+      const rows = [...(emailRes.rows ?? []), ...(formRes.rows ?? [])]
+        .sort((a, b) => (b.received?.getTime() ?? 0) - (a.received?.getTime() ?? 0))
+      if (!rows.length) {
+        toast('Nothing to export in this view', 'info')
+        return
+      }
+      const esc = (v) => {
+        const s = v == null ? '' : String(v)
+        return /[",\n]/.test(s) ? `"${s.replaceAll('"', '""')}"` : s
+      }
+      const header = ['Name', 'Email', 'Phone', 'Position', 'Channel', 'Source', 'Received', 'Status', 'City', 'Notice period', 'ATS score', 'Assigned job']
+      const lines = [header.join(',')]
+      for (const r of rows) {
+        lines.push([
+          r.name, r.email, r.phone, r.position,
+          r.kind === 'form' ? 'Sheet Form' : 'Email',
+          r.source,
+          r.received ? r.received.toISOString().slice(0, 10) : '',
+          r.processing, r.residingCity, r.noticePeriod, r.atsScore,
+          r.assignedPost?.title,
+        ].map(esc).join(','))
+      }
+      // BOM so Excel opens it as UTF-8 rather than mangling names.
+      const blob = new Blob([String.fromCharCode(0xFEFF) + lines.join('\n')], { type: 'text/csv;charset=utf-8' })
+      const a = document.createElement('a')
+      a.href = URL.createObjectURL(blob)
+      a.download = `inbox-${channel}-${tab.toLowerCase().replaceAll(' ', '-')}-${new Date().toISOString().slice(0, 10)}.csv`
+      a.click()
+      URL.revokeObjectURL(a.href)
+      toast(`Exported ${rows.length} application${rows.length === 1 ? '' : 's'}`, 'success')
+    } catch (err) {
+      toast(friendlyAuthError(err, 'Export failed'), 'error')
+    } finally {
+      setExporting(false)
+    }
+  }
+
   const [syncRunId, setSyncRunId] = useState(() => readStoredSyncRunId())
   const syncToastShown = useRef(null)
 
@@ -1135,6 +1192,9 @@ export default function Inbox() {
               onClick={() => sync.mutate()}
             />
           )}
+          <button className="btn btn-secondary" onClick={exportCsv} disabled={exporting}>
+            <Icon name="download" /> {exporting ? 'Exporting…' : 'Export'}
+          </button>
           <button className="btn btn-primary" onClick={() => navigate('/import')}>
             <Icon name="upload" /> Upload CVs
           </button>
@@ -1212,11 +1272,31 @@ export default function Inbox() {
                 {activeQuery.isPending && (
                   <SkeletonRows rows={6} />
                 )}
-                {activeQuery.isError && (
+                {/* The big error state only when there is truly nothing to
+                    show — cached rows beat a scary banner over a working list. */}
+                {activeQuery.isError && list.length === 0 && (
                   <EmptyState icon="inbox" title={isForms ? "Couldn't load form applicants" : "Couldn't load applications"}>
                     {friendlyAuthError(activeQuery.error, 'Request failed')}
                   </EmptyState>
                 )}
+                {/* All channel with one source down: keep the healthy list,
+                    note the gap in one line instead of a full error state. */}
+                {isAllChannel && applicationsQuery.isError !== formQuery.isError
+                  && (applicationsQuery.isError || formQuery.isError) && (
+                  <div
+                    className="cell-sub"
+                    style={{
+                      padding: '9px 16px',
+                      borderBottom: '1px solid var(--border)',
+                      background: 'var(--warning-soft)',
+                      color: 'var(--warning)',
+                    }}
+                  >
+                    {applicationsQuery.isError
+                      ? 'Email applications couldn’t load right now — showing Sheet Forms only.'
+                      : 'Sheet Form applications couldn’t load right now — showing Email only.'}
+                  </div>
+                )}
                 {activeQuery.isSuccess && list.length === 0 ? (
                   <EmptyState icon="inbox" title="Nothing here">
                     {isForms ? 'No form responses in this sheet tab.' : 'No applications in this view.'}