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/lib/offline/pack-fallback.ts

@@ -0,0 +1,32 @@
+import { listPacks } from "@/lib/apiaries/offline-pack";
+import type { StoredPack } from "./db";
+import { isNetworkError } from "@/lib/http/fetch-with-timeout";
+
+/**
+ * The server's answer - or, only when the network failed, what the user's
+ * offline packs say. A server refusal (ApiError: 403, 404, 400 ...) is never
+ * covered up with pack data: the server knows better than an old pack.
+ * When the packs have nothing (`fromPacks` returns null) or cannot be read,
+ * the network error is passed on, so the caller shows "not loaded".
+ *
+ * Queries built on this read local storage when offline: give them
+ * `networkMode: "always"`, or a paused retry would hide the fallback.
+ */
+export async function withPackFallback<T>(
+  fetcher: () => Promise<T>,
+  fromPacks: (packs: StoredPack[]) => T | null,
+  ownerUserId: string,
+): Promise<T> {
+  try {
+    return await fetcher();
+  } catch (error) {
+    if (!isNetworkError(error)) {
+      throw error;
+    }
+    const fallback = await listPacks(ownerUserId).then(fromPacks, () => null);
+    if (fallback === null) {
+      throw error;
+    }
+    return fallback;
+  }
+}