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.spec.ts

@@ -0,0 +1,73 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { ApiError } from "@/lib/auth/api-client";
+import { listPacks } from "@/lib/apiaries/offline-pack";
+import { offlinePack, storedPack } from "@/lib/apiaries/offline-pack.fixtures";
+import { withPackFallback } from "./pack-fallback";
+
+vi.mock("@/lib/apiaries/offline-pack", () => ({ listPacks: vi.fn() }));
+
+const PACKS = [storedPack(offlinePack({ apiaryId: "apiary-1", apiaryName: "Obstwiese" }))];
+
+const apiaryNames = vi.fn((packs: typeof PACKS) => packs.map((pack) => pack.pack.apiary.name));
+
+describe("withPackFallback", () => {
+  beforeEach(() => {
+    vi.mocked(listPacks).mockReset().mockResolvedValue(PACKS);
+    apiaryNames.mockClear();
+  });
+
+  it("answers from the server whenever the server answers", async () => {
+    const result = await withPackFallback(async () => ["vom Server"], apiaryNames, "user-1");
+
+    expect(result).toEqual(["vom Server"]);
+    expect(listPacks).not.toHaveBeenCalled();
+  });
+
+  it("falls back to the pack on a network error", async () => {
+    const result = await withPackFallback(
+      () => Promise.reject(new TypeError("Failed to fetch")),
+      apiaryNames,
+      "user-1",
+    );
+
+    expect(result).toEqual(["Obstwiese"]);
+    expect(listPacks).toHaveBeenCalledWith("user-1");
+  });
+
+  it("falls back to the pack when the request timed out", async () => {
+    const timeout = new DOMException("Zeitüberschreitung der Anfrage", "TimeoutError");
+
+    const result = await withPackFallback(() => Promise.reject(timeout), apiaryNames, "user-1");
+
+    expect(result).toEqual(["Obstwiese"]);
+  });
+
+  it("rethrows an ApiError instead of showing pack data", async () => {
+    for (const status of [403, 404, 500]) {
+      const rejection = new ApiError(status, "Nein");
+
+      await expect(
+        withPackFallback(() => Promise.reject(rejection), apiaryNames, "user-1"),
+      ).rejects.toBe(rejection);
+    }
+    expect(listPacks).not.toHaveBeenCalled();
+    expect(apiaryNames).not.toHaveBeenCalled();
+  });
+
+  it("rethrows when the pack has nothing", async () => {
+    const offline = new TypeError("Failed to fetch");
+
+    await expect(
+      withPackFallback(() => Promise.reject(offline), () => null, "user-1"),
+    ).rejects.toBe(offline);
+  });
+
+  it("rethrows the network error when the packs cannot be read", async () => {
+    const offline = new TypeError("Failed to fetch");
+    vi.mocked(listPacks).mockRejectedValue(new Error("IndexedDB gesperrt"));
+
+    await expect(
+      withPackFallback(() => Promise.reject(offline), apiaryNames, "user-1"),
+    ).rejects.toBe(offline);
+  });
+});