Persist collector state and stabilize download controls

Persist collector packages and disclosure state through validated atomic AppData storage with backup recovery and shutdown synchronization. Align download sidebar metrics with the hidden-extracted presentation scope and keep Start available through temporary Real-Debrid cooldowns while preserving hard account blocks.

tests/main-shutdown-lifecycle.test.ts

@@ -73,6 +73,33 @@ afterEach(() => {
 });
 
 describe("main shutdown lifecycle", () => {
+  it("continues the full shutdown when the collector state cannot be flushed", async () => {
+    const controller = Object.create(AppController.prototype) as any;
+    controller.runtimeStatsTimer = null;
+    controller.collectorStore = { flushSync: vi.fn(() => { throw new Error("collector locked"); }) };
+    controller.notificationOutbox = { drainForShutdown: vi.fn(async () => undefined) };
+    controller.manager = {
+      suspendDownloadHealthMonitoring: vi.fn(),
+      prepareForShutdown: vi.fn(),
+      flushNotificationsForShutdown: vi.fn(async () => undefined)
+    };
+    controller.downloadHealthTimer = null;
+    controller.downloadHealthEvaluation = null;
+    controller.downloadHealthMonitor = null;
+    controller.megaWebFallback = { dispose: vi.fn() };
+    controller.realDebridWebFallbacks = new Map();
+    controller.pendingRealDebridWebAccountIds = new Map();
+    controller.allDebridWebFallback = { dispose: vi.fn() };
+    controller.bestDebridWebFallback = { dispose: vi.fn() };
+    controller.shutdownLogStorage = vi.fn();
+    controller.audit = vi.fn();
+    controller.settings = { historyRetentionMode: "never" };
+
+    await expect(controller.shutdown()).resolves.toBeUndefined();
+    expect(controller.manager.prepareForShutdown).toHaveBeenCalledTimes(1);
+    expect(controller.shutdownLogStorage).toHaveBeenCalledTimes(1);
+  });
+
   it("AppController waits for the bounded outbox drain before disposing runtime owners", async () => {
     const drain = deferred();
     const manager = { prepareForShutdown: vi.fn() };