feat: platform backbone and field capture complete (checkpoint)

Platform backbone (plan 2026-10-13-plattform-rueckgrat), all tasks reviewed:
- webhooks with delivery table, retries and stable delivery id
- calendar handlers; a finished task removes its Outlook event
- tasks, automations, inspections, varroa, treatments, feedings,
  harvests, colonies, wintering, stock and bottling record domain events
  in the same transaction; legacy post-commit calls removed
- row locks through one helper (lockRowForUpdate, lockRowsForShare,
  lockRowsForUpdate)
- job framework with JobRun, cli exit codes, cleanup, task templates,
  daily evaluation, hourly app-backup and the rekey job
- system API and page "Verwaltung > System" with retry
- @nestjs/schedule removed, guard tests against in-process schedulers

Field capture T3 (plan 2026-10-13-t3-erfassung-am-stand), all tasks reviewed:
- inspection photo offline without metadata
- bulk capture for treatments, feedings and varroa (backend + frontend)
- offline stand mode with service worker, offline pages and packs
- offline session, cold start and logout on shared devices

Docs: ARCHITECTURE.md assumptions and sections updated, TASKS.md.
Gates: backend lint, typecheck, 1770 unit, 420 e2e, build, no schema
drift; frontend lint, typecheck, 913 tests, build. Not rolled out.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Frontend/src/components/offline/offline-band.tsx

@@ -17,7 +17,8 @@ import { PendingQueueSheet } from "./pending-queue-sheet";
 const COUNT_INTERVAL_MS = 15_000;
 const EMPTY_QUEUE: QueueSummary = { own: 0, failed: 0, foreign: 0 };
 // Both auto-sync triggers can fire together; they share one sync run
-// (syncPendingEntries), and one toast id keeps it to one message.
+// (syncPendingEntries), even one already running - they change nothing that
+// is to be sent - and one toast id keeps it to one message.
 const SYNC_TOAST_ID = "offline-sync";
 // Wraps on narrow phones instead of overflowing; never below 44 px.
 const BAND_BUTTON_CLASS = "h-auto min-h-11 whitespace-normal text-left";
@@ -26,6 +27,12 @@ interface OfflineBandProps {
   userId: string;
   /** Focus target when the queue sheet closes and the band shows nothing. */
   pageContentRef: RefObject<HTMLElement | null>;
+  /**
+   * False in an offline session (opened from the cached identity, no access
+   * token): the band then shows what waits but neither opens the sync gate
+   * nor sends - the server would only answer 401.
+   */
+  syncEnabled?: boolean;
 }
 
 /**
@@ -33,7 +40,7 @@ interface OfflineBandProps {
  * device, how much still waits to be sent and what the server rejected.
  * Sends by itself as soon as the connection is back.
  */
-export function OfflineBand({ userId, pageContentRef }: OfflineBandProps) {
+export function OfflineBand({ userId, pageContentRef, syncEnabled = true }: OfflineBandProps) {
   const queryClient = useQueryClient();
   const connectivity = useConnectivity();
   const statusRef = useRef<HTMLDivElement>(null);
@@ -68,24 +75,31 @@ export function OfflineBand({ userId, pageContentRef }: OfflineBandProps) {
 
   // The band only exists for a signed-in user, and the auth context sets that
   // user's access token before the user: the moment to reopen sync after a
-  // logout's cancelSync(). Declared first, so it runs before the sync below.
+  // logout's cancelSync(). Not without a token (offline session): the gate
+  // stays closed until the session is online. Declared first, so it runs
+  // before the sync below.
   useEffect(() => {
-    resumeSync();
-  }, [userId]);
+    if (syncEnabled) {
+      resumeSync();
+    }
+  }, [userId, syncEnabled]);
 
   // Mount, and every switch back to online (a request reached the server again).
   useEffect(() => {
-    if (connectivity === "online") {
+    if (syncEnabled && connectivity === "online") {
       startSync();
     }
-  }, [connectivity, startSync, userId]);
+  }, [connectivity, startSync, userId, syncEnabled]);
 
   // The browser's own `online` event: try even while the last request failed.
   useEffect(() => {
+    if (!syncEnabled) {
+      return;
+    }
     const handleOnline = () => startSync();
     window.addEventListener("online", handleOnline);
     return () => window.removeEventListener("online", handleOnline);
-  }, [startSync]);
+  }, [startSync, syncEnabled]);
 
   // The sheet stays open while the user still has entries in it (waiting
   // ones too, after the last rejected one was discarded), and closes once
@@ -95,7 +109,8 @@ export function OfflineBand({ userId, pageContentRef }: OfflineBandProps) {
     setSheetOpen(false);
   }
 
-  const isOffline = connectivity === "offline";
+  // An offline session cannot send, whatever the network says.
+  const isOffline = connectivity === "offline" || !syncEnabled;
   const hasContent = isOffline || queue.own > 0 || hasRejected;
 
   // Back to the trigger while it exists; otherwise to the band's message, or