fix: address final review findings (order-notification watcher robustness)

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

src/app/features/admin/shell/admin-layout.component.scss

@@ -367,6 +367,8 @@
   right: 0;
   top: calc(100% + 8px);
   width: 240px;
+  max-height: 60vh;
+  overflow-y: auto;
   padding: var(--space-md);
   background: var(--bg-primary);
   border: 1px solid var(--border-color);

src/app/features/admin/shell/admin-layout.component.spec.ts

@@ -30,6 +30,7 @@ describe('AdminLayoutComponent notifications bell', () => {
     recentOrders: ReturnType<typeof signal<AdminOrder[]>>;
     unreadCount: ReturnType<typeof signal<number>>;
     start: jasmine.Spy;
+    stop: jasmine.Spy;
     markAllSeen: jasmine.Spy;
   };
 
@@ -38,6 +39,7 @@ describe('AdminLayoutComponent notifications bell', () => {
       recentOrders: signal<AdminOrder[]>([makeOrder('o1', '1001')]),
       unreadCount: signal(1),
       start: jasmine.createSpy('start'),
+      stop: jasmine.createSpy('stop'),
       markAllSeen: jasmine.createSpy('markAllSeen'),
     };
 
@@ -73,4 +75,11 @@ describe('AdminLayoutComponent notifications bell', () => {
     expect(component.notificationsOpen()).toBe(false);
     expect(watcherStub.markAllSeen).toHaveBeenCalledTimes(1);
   });
+
+  it('stops the watcher when the component is destroyed', () => {
+    const fixture = TestBed.createComponent(AdminLayoutComponent);
+    fixture.detectChanges();
+    fixture.destroy();
+    expect(watcherStub.stop).toHaveBeenCalledTimes(1);
+  });
 });

src/app/features/admin/shell/admin-layout.component.ts

@@ -93,6 +93,7 @@ export class AdminLayoutComponent {
   constructor() {
     this.readRouteData();
     this.orderWatcher.start();
+    this.destroyRef.onDestroy(() => this.orderWatcher.stop());
     this.router.events
       .pipe(
         filter(event => event instanceof NavigationEnd),

src/app/features/admin/shell/services/admin-order-watcher.service.spec.ts

@@ -48,7 +48,10 @@ describe('AdminOrderWatcherService', () => {
       [makeOrder('o2', '1002', '2026-08-15T10:00:00.000Z'), makeOrder('o1', '1001', '2026-08-15T09:00:00.000Z')],
     ];
 
-    localStorage.clear();
+    localStorage.removeItem('adminOrderWatcher.lastNotifiedOrderId.v1');
+    localStorage.removeItem('adminOrderWatcher.lastNotifiedOrderCreatedAt.v1');
+    localStorage.removeItem('adminOrderWatcher.lastAcknowledgedOrderId.v1');
+    localStorage.removeItem('adminOrderWatcher.pollIntervalMs.v1');
 
     TestBed.configureTestingModule({
       providers: [
@@ -110,13 +113,53 @@ describe('AdminOrderWatcherService', () => {
   }));
 
   it('setIntervalSeconds updates intervalMs and rejects invalid values', () => {
-    service.setIntervalSeconds(30);
+    expect(service.setIntervalSeconds(30)).toBe(true);
     expect(service.intervalMs()).toBe(30000);
 
-    service.setIntervalSeconds(0);
+    expect(service.setIntervalSeconds(0)).toBe(false);
     expect(service.intervalMs()).toBe(30000);
 
-    service.setIntervalSeconds(-5);
+    expect(service.setIntervalSeconds(-5)).toBe(false);
     expect(service.intervalMs()).toBe(30000);
   });
+
+  it('falls back to a timestamp comparison (not the whole page) when the last-notified order id disappears', fakeAsync(() => {
+    service.start();
+    tick(0);
+
+    // Second poll: 'o2' (the last-notified id) is gone. Page contains orders
+    // both older and newer than o2's createdAt (2026-08-15T10:00:00.000Z).
+    pollIndex = 1;
+    ordersByPoll.push([
+      makeOrder('o5', '1005', '2026-08-15T12:00:00.000Z'),
+      makeOrder('o4', '1004', '2026-08-15T11:00:00.000Z'),
+      makeOrder('o3', '1003', '2026-08-15T10:30:00.000Z'),
+      makeOrder('o0', '1000', '2026-08-15T08:00:00.000Z'),
+    ]);
+
+    tick(service.intervalMs());
+
+    // Only o5, o4, o3 are newer than o2's createdAt - o0 must not toast.
+    expect(notifications.notifications().length).toBe(3);
+    const messages = notifications.notifications().map(n => n.message);
+    expect(messages.some(m => m.includes('1005'))).toBe(true);
+    expect(messages.some(m => m.includes('1004'))).toBe(true);
+    expect(messages.some(m => m.includes('1003'))).toBe(true);
+    expect(messages.some(m => m.includes('1000'))).toBe(false);
+  }));
+
+  it('stop() clears the interval so no further polls occur', fakeAsync(() => {
+    const gateway = TestBed.inject(AdminOrdersLocalGateway);
+    const loadOrdersSpy = spyOn(gateway, 'loadOrders').and.callThrough();
+
+    service.start();
+    tick(0);
+    const callsAfterStart = loadOrdersSpy.calls.count();
+
+    tick(service.intervalMs() / 2);
+    service.stop();
+    tick(service.intervalMs() * 2);
+
+    expect(loadOrdersSpy.calls.count()).toBe(callsAfterStart);
+  }));
 });

src/app/features/admin/shell/services/admin-order-watcher.service.ts

@@ -7,6 +7,7 @@ import { LanguageService } from '../../../../services/language.service';
 import { TranslateService } from '../../../../i18n/translate.service';
 
 const LAST_NOTIFIED_KEY = 'adminOrderWatcher.lastNotifiedOrderId.v1';
+const LAST_NOTIFIED_AT_KEY = 'adminOrderWatcher.lastNotifiedOrderCreatedAt.v1';
 const LAST_ACKNOWLEDGED_KEY = 'adminOrderWatcher.lastAcknowledgedOrderId.v1';
 const POLL_INTERVAL_KEY = 'adminOrderWatcher.pollIntervalMs.v1';
 export const DEFAULT_POLL_INTERVAL_MS = 15000;
@@ -44,6 +45,7 @@ export class AdminOrderWatcherService {
   readonly intervalMs: Signal<number> = this.intervalMsSignal.asReadonly();
 
   private lastNotifiedOrderId: string | null = this.storage.getItem(LAST_NOTIFIED_KEY);
+  private lastNotifiedOrderCreatedAt: string | null = this.storage.getItem(LAST_NOTIFIED_AT_KEY);
   private timerId: ReturnType<typeof setInterval> | null = null;
   private started = false;
 
@@ -56,9 +58,17 @@ export class AdminOrderWatcherService {
     this.scheduleNext();
   }
 
-  setIntervalSeconds(seconds: number): void {
+  stop(): void {
+    if (this.timerId !== null) {
+      clearInterval(this.timerId);
+      this.timerId = null;
+    }
+    this.started = false;
+  }
+
+  setIntervalSeconds(seconds: number): boolean {
     if (!Number.isFinite(seconds) || seconds < MIN_POLL_INTERVAL_MS / 1000) {
-      return;
+      return false;
     }
     const ms = Math.round(seconds * 1000);
     this.intervalMsSignal.set(ms);
@@ -66,14 +76,16 @@ export class AdminOrderWatcherService {
     if (this.started) {
       this.scheduleNext();
     }
+    return true;
   }
 
   markAllSeen(): void {
-    const newestId = this.recentOrdersSignal()[0]?.id ?? null;
-    this.lastAcknowledgedOrderIdSignal.set(newestId);
-    if (newestId) {
-      this.storage.setItem(LAST_ACKNOWLEDGED_KEY, newestId);
+    const newestId = this.recentOrdersSignal()[0]?.id;
+    if (!newestId) {
+      return;
     }
+    this.lastAcknowledgedOrderIdSignal.set(newestId);
+    this.storage.setItem(LAST_ACKNOWLEDGED_KEY, newestId);
   }
 
   private scheduleNext(): void {
@@ -99,10 +111,21 @@ export class AdminOrderWatcherService {
 
     const isFirstPoll = this.lastNotifiedOrderId === null;
     const notifyIndex = isFirstPoll ? -1 : items.findIndex(order => order.id === this.lastNotifiedOrderId);
-    const newOrders = isFirstPoll ? [] : (notifyIndex === -1 ? items : items.slice(0, notifyIndex));
+    // When the last-notified order id is no longer present in the current page
+    // (deleted, or more than RECENT_ORDERS_LIMIT orders arrived since the last
+    // poll), fall back to a timestamp comparison instead of treating the whole
+    // page as new - otherwise a single missing id could fire a burst of up to
+    // RECENT_ORDERS_LIMIT toasts.
+    const newOrders = isFirstPoll
+      ? []
+      : notifyIndex !== -1
+        ? items.slice(0, notifyIndex)
+        : items.filter(order => this.lastNotifiedOrderCreatedAt !== null && order.createdAt > this.lastNotifiedOrderCreatedAt);
 
     this.lastNotifiedOrderId = items[0].id;
+    this.lastNotifiedOrderCreatedAt = items[0].createdAt;
     this.storage.setItem(LAST_NOTIFIED_KEY, this.lastNotifiedOrderId);
+    this.storage.setItem(LAST_NOTIFIED_AT_KEY, this.lastNotifiedOrderCreatedAt);
 
     if (isFirstPoll) {
       // Nothing existed to compare against yet - treat current orders as already