Inject the notification senders instead of importing them lazily

Nine fire-and-forget sends reached notifications.bridge through
import('...').then(({ send }) => ...). The laziness was working around a
module cycle that no longer exists, and it cost twice: it hid the edge from
the module graph, and it handed each send a NotificationsService built
outside the container rather than the container's own.

The sweep needed a method rather than a grep. tests/ sits outside
tsconfig's include, so a service that gains a constructor parameter does not
break its hand-wired call sites at compile time — the argument arrives as
undefined and throws inside the send. Adding tests to a throwaway tsconfig
and diffing the errors before and after named all 46 sites exactly. The same
config reports 288 pre-existing errors in the suites, almost all deliberate
partial constructions in the harnesses, which is why tests/ is not in the
build's include; that cleanup is its own piece of work and is written down
in the nest README.

notifications.instance.ts holds the out-of-container instance, apart from
notifications.bridge.ts on purpose: several suites replace the bridge
wholesale with vi.mock(..., () => ({ send })), and a sibling bridge taking
its instance from there would break under those mocks.

The suites that assert on a send now hand their spy to the injected service.
The reservations e2e overrides the provider, because its app resolves the
real one out of its own container and never saw the module mock.

server/tests/helpers/mcp-test-controllers.ts

@@ -66,6 +66,7 @@ import { PlacePhotoCacheService } from '../../src/nest/place-photos/place-photo-
 import { RuntimeEnvService } from '../../src/nest/app-config/runtime-env.service';
 import { makeNotificationsService, makeNotificationPreferencesService } from './notifications';
 import { AddonsService } from '../../src/nest/addons/addons.service';
+import { notificationsStub } from './notifications';
 
 /**
  * Hand-wired counterpart of the boot-time discovery in McpRegistryService,
@@ -84,8 +85,8 @@ export function createMcpTestRegistry(): McpRegistry {
   const exchangeRatesService = new ExchangeRatesService();
   const budgetService = new BudgetService(dbService, permissionsService, exchangeRatesService, realtimeService);
   const todoService = new TodoService(dbService, permissionsService, realtimeService);
-  const packingService = new PackingService(dbService, permissionsService, realtimeService);
-  const collabService = new CollabService(dbService, permissionsService, realtimeService);
+  const packingService = new PackingService(dbService, permissionsService, realtimeService, notificationsStub());
+  const collabService = new CollabService(dbService, permissionsService, realtimeService, notificationsStub());
   const mapsService = new MapsService(dbService);
   const journeyDomain = new JourneyDomainService(dbService, realtimeService, new TrekPhotosRepository(dbService));
   // The last three were previously omitted, which left them `undefined` at
@@ -98,16 +99,16 @@ export function createMcpTestRegistry(): McpRegistry {
     new PlacePhotoCacheService(dbService, new RuntimeEnvService()),
     journeyDomain,
   );
-  const reservationsService = new ReservationsService(dbService, permissionsService, budgetService, realtimeService);
+  const reservationsService = new ReservationsService(dbService, permissionsService, budgetService, realtimeService, notificationsStub());
   const accommodationsService = new AccommodationsService(dbService, permissionsService, realtimeService);
-  const membersService = new TripMembersService(dbService, budgetService, new UserCleanupService(dbService), permissionsService, realtimeService);
+  const membersService = new TripMembersService(dbService, budgetService, new UserCleanupService(dbService), permissionsService, realtimeService, notificationsStub());
   const tripsService = new TripsService(
     dbService,
     reservationsService,
     daysService,
     permissionsService,
     budgetService,
-    new VacayService(dbService, realtimeService),
+    new VacayService(dbService, realtimeService, notificationsStub()),
     realtimeService,
     new UnsplashService(dbService, new RuntimeEnvService()),
   );
@@ -142,12 +143,12 @@ export function createMcpTestRegistry(): McpRegistry {
       new AccommodationsMcp(accommodationsService, dbService, placesService, authService),
       new AssignmentsMcp(assignmentsService, daysService, authService),
       new CollabMcp(collabService, authService, addonsService),
-      new VacayMcp(new VacayService(dbService, realtimeService), authService, addonsService),
+      new VacayMcp(new VacayService(dbService, realtimeService, notificationsStub()), authService, addonsService),
       new TripsMcp(tripsService, todoService, collabService, authService, calendarService, membersService, readModelService, addonsService),
       new ShareMcp(new ShareService(dbService, new SettingsService(dbService), permissionsService, queryHelpersService), authService),
       new MapsMcp(mapsService),
       new PlacesMcp(placesService, mapsService, dbService, authService, journeyDomain),
-      new CollectionsMcp(new CollectionsService(dbService, permissionsService, realtimeService), dbService, authService, addonsService),
+      new CollectionsMcp(new CollectionsService(dbService, permissionsService, realtimeService, notificationsStub()), dbService, authService, addonsService),
       new TransitMcp(new TransitService(), daysService, reservationsService, dbService, authService),
       new AtlasMcp(new AtlasService(dbService), addonsService, authService),
       new JourneyMcp(journeyDomain, new JourneyShareService(dbService, journeyDomain), addonsService, authService),