feat: instant notifications + Notifications screen

- NotificationPoller polls every 30s while app is in foreground
- Poller auto-starts on resume, stops on pause
- New NotificationsScreen with mark-as-read, mark-all-read, infinite scroll
- Bottom nav: Alerts tab with unread badge
- Dashboard: bell icon with unread badge
- Backend: GET /api/notifications/unread-count endpoint
- App version 1.1.0

src/Controllers/ApiController.php

@@ -496,6 +496,19 @@ class ApiController
         ]);
     }
 
+    public function unreadCount(): void
+    {
+        $user = $this->authenticateRequest();
+
+        $notificationModel = new \ServerManager\Models\Notification();
+        $count = $notificationModel->getUnreadCount((int) $user['id']);
+
+        $this->view->json([
+            'success' => true,
+            'unread_count' => $count,
+        ]);
+    }
+
     public function notifications(): void
     {
         $user = $this->authenticateRequest();