Add in-app + real-time notifications (SignalR/mock, Iran-friendly)

- AppNotification + OnlineService.onNotification (hub event + mock periodic) —
  no FCM/APNs (blocked in Iran); uses the existing realtime channel
- notification-store + pushNotification(); 🔔 bell with unread badge in TopBar,
  notifications screen, global toaster (plays notify sfx)
- Wired events: daily reward, post-match achievements, friend requests
- Closed-app push (Pushe/Najva/Chabok) noted as a later step (needs provider keys)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/lib/online/signalr-service.ts

@@ -10,6 +10,7 @@ import {
   Unsubscribe,
 } from "./service";
 import {
+  AppNotification,
   AuthSession,
   ChatMessage,
   Conversation,
@@ -48,6 +49,8 @@ export class SignalrService implements OnlineService {
   private mmCbs = new Set<(s: MatchmakingState) => void>();
   private stateCbs = new Set<(s: ServerGameState) => void>();
   private reactionCbs = new Set<(seat: number, reaction: string) => void>();
+  private notifCbs = new Set<(n: AppNotification) => void>();
+  private mockNotifUnsub?: () => void;
 
   constructor() {
     if (typeof window !== "undefined") {
@@ -89,6 +92,8 @@ export class SignalrService implements OnlineService {
     conn.on("state", (s: ServerGameState) => this.stateCbs.forEach((cb) => cb(s)));
     conn.on("reaction", (r: { seat: number; reaction: string }) =>
       this.reactionCbs.forEach((cb) => cb(r.seat, r.reaction)));
+    conn.on("notification", (n: AppNotification) =>
+      this.notifCbs.forEach((cb) => cb(n)));
 
     this.conn = conn;
     try {
@@ -262,6 +267,14 @@ export class SignalrService implements OnlineService {
   markRead(id: string) { return this.mock.markRead(id); }
   onChat(cb: (id: string, m: ChatMessage[]) => void) { return this.mock.onChat(cb); }
 
+  onNotification(cb: (n: AppNotification) => void): Unsubscribe {
+    this.notifCbs.add(cb);
+    // also forward the mock's periodic notifications for liveliness
+    if (!this.mockNotifUnsub)
+      this.mockNotifUnsub = this.mock.onNotification((n) => this.notifCbs.forEach((c) => c(n)));
+    return () => this.notifCbs.delete(cb);
+  }
+
   async getOnlineCount(): Promise<number> {
     try {
       const res = await fetch(`${SERVER}/api/stats/online`);