fix(navigator): restore useNotification() inside useNavigatorStore

Commit 8ab0021a introduced an unjustified deviation: it removed the
useNotification() call from inside useNavigatorStore and replaced it
with a module-level _simpleAlert ref + _injectSimpleAlert() exported
function, on the theory that nested useBetween calls corrupt
use-between's state.

That diagnosis is wrong. Production proof:
- useCatalog.ts:56 calls useNotification() inside useCatalogStore
- useWiredToolsStore.ts:131 calls useNotification() inside its store
- The original useNavigator.ts:32 calls useNotification() inside its
  state closure
All three have been in production for ages without issue. Nested
useBetween calls work fine.

The smoke-test failure that prompted the workaround was a mock issue,
not a real bug. Reverting to the standard pattern — useNotification()
direct inside the useBetween store closure. Production alerts work
again immediately without requiring an explicit injection call from
consumers.

Mock additions (src/nitro-renderer.mock.ts):
- Added 23 notification MessageEvent subclasses (AchievementNotification-
  MessageEvent, ActivityPoint..., BadgeReceived, ClubGiftNotification,
  ClubGiftSelected, ConnectionError, HabboBroadcast, HotelClosedAndOpens,
  HotelClosesAndWillOpenAt, HotelWillCloseInMinutes, InfoFeedEnable,
  MaintenanceStatus, ModeratorCaution, ModeratorMessage, MOTD,
  NotificationDialog, PetLevel, PetReceived, RespectReceived, RoomEnter,
  SimpleAlert, UserBanned, WiredRewardResult) so useNotificationStore
  can register its listeners without throwing.
- Added RoomEnterEffect stub (isRunning: false, totalRunningTime: 0).
- Added WiredRewardResultMessageEvent static constants.

src/nitro-renderer.mock.ts

@@ -274,6 +274,48 @@ export class UserFlatCatsEvent extends MessageEvent {}
 export class UserInfoEvent extends MessageEvent {}
 export class UserPermissionsEvent extends MessageEvent {}
 
+// ---------------------------------------------------------------------------
+// Notification event classes — MessageEvent subclasses needed by
+// useNotificationStore (called via useNotification() inside useNavigatorStore).
+// The real renderer classes take a `callBack` constructor arg; the pattern
+// here is the same as the Navigator event stubs above.
+// ---------------------------------------------------------------------------
+
+export class AchievementNotificationMessageEvent extends MessageEvent {}
+export class ActivityPointNotificationMessageEvent extends MessageEvent {}
+export class BadgeReceivedEvent extends MessageEvent {}
+export class ClubGiftNotificationEvent extends MessageEvent {}
+export class ClubGiftSelectedEvent extends MessageEvent {}
+export class ConnectionErrorEvent extends MessageEvent {}
+export class HabboBroadcastMessageEvent extends MessageEvent {}
+export class HotelClosedAndOpensEvent extends MessageEvent {}
+export class HotelClosesAndWillOpenAtEvent extends MessageEvent {}
+export class HotelWillCloseInMinutesEvent extends MessageEvent {}
+export class InfoFeedEnableMessageEvent extends MessageEvent {}
+export class MaintenanceStatusMessageEvent extends MessageEvent {}
+export class ModeratorCautionEvent extends MessageEvent {}
+export class ModeratorMessageEvent extends MessageEvent {}
+export class MOTDNotificationEvent extends MessageEvent {}
+export class NotificationDialogMessageEvent extends MessageEvent {}
+export class PetLevelNotificationEvent extends MessageEvent {}
+export class PetReceivedMessageEvent extends MessageEvent {}
+export class RespectReceivedEvent extends MessageEvent {}
+export class RoomEnterEvent extends MessageEvent {}
+export class SimpleAlertMessageEvent extends MessageEvent {}
+export class UserBannedMessageEvent extends MessageEvent {}
+export class WiredRewardResultMessageEvent extends MessageEvent
+{
+    static readonly PRODUCT_DONATED_CODE = 7;
+    static readonly BADGE_DONATED_CODE = 8;
+}
+
+// RoomEnterEffect — used by useNotificationStore to check if the room-enter
+// animation is still running before showing the mod disclaimer bubble.
+export const RoomEnterEffect = {
+    isRunning: () => false,
+    totalRunningTime: 0
+};
+
 export class RoomEngineObjectEvent extends StubClass {}
 export class CreateLinkEvent extends StubClass {}
 export class EventDispatcher extends StubClass {}