Add the Recent updates sheet behind the Home bell (Feature 21)

GET /api/v1/updates lists the last 10 distinct notification events from
the outbox, newest first and one per event key whatever its channels.
POST /api/v1/updates/seen {"through": created_at} moves
household_settings.updates_seen_at forward, so /api/v1/home's
recentUpdates.unread is true only for an event stored since. The Home
bell opens a Sheet listing the updates with relative times; a row opens
its URL, and opening the sheet marks the updates seen, clearing the
grape dot optimistically and putting it back if the mark fails.

Maestro task 96e2dc3f-1f8a-4114-bcb5-e0f93c349165.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/server/server_test.go

@@ -52,13 +52,19 @@ func newTestRouter(t *testing.T, version string) http.Handler {
 }
 
 func newTestRouterWith(t *testing.T, version string, settings *household.SettingsService, runner *jobs.Runner) http.Handler {
+	t.Helper()
+	return newTestRouterWithHome(t, version, settings, runner, newTestHome(t))
+}
+
+// newTestRouterWithHome is newTestRouterWith serving Home from homeSvc.
+func newTestRouterWithHome(t *testing.T, version string, settings *household.SettingsService, runner *jobs.Runner, homeSvc *home.Service) http.Handler {
 	t.Helper()
 	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
 	assets := fstest.MapFS{
 		"index.html":             {Data: []byte(fixtureIndex)},
 		"assets/index-AbC123.js": {Data: []byte(fixtureAsset)},
 	}
-	r, err := NewRouter(logger, version, nil, stubAuth{}, stubSessions{}, settings, newTestSearch(t), newTestAI(t), newTestChat(t), newTestDinners(t), newTestSuggest(t), newTestPlan(t), newTestShopping(t), newTestGoogle(t), newTestPush(t), newTestIdeas(t), newTestHome(t), runner, newTestPhotos(t), assets)
+	r, err := NewRouter(logger, version, nil, stubAuth{}, stubSessions{}, settings, newTestSearch(t), newTestAI(t), newTestChat(t), newTestDinners(t), newTestSuggest(t), newTestPlan(t), newTestShopping(t), newTestGoogle(t), newTestPush(t), newTestIdeas(t), homeSvc, runner, newTestPhotos(t), assets)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -265,7 +271,13 @@ func newTestShopping(t *testing.T) *shopping.Service {
 // connection. One database keeps the routers that never ask for Home cheap.
 func newTestHome(t *testing.T) *home.Service {
 	t.Helper()
-	st := newTestStore(t)
+	return newTestHomeOn(t, newTestStore(t))
+}
+
+// newTestHomeOn returns a home service over st, a migrated database, which
+// it seeds with zone America/New_York and the seed notification preferences.
+func newTestHomeOn(t *testing.T, st *store.Store) *home.Service {
+	t.Helper()
 	if err := household.SeedSettings(context.Background(), st, "America/New_York"); err != nil {
 		t.Fatal(err)
 	}