feat: Phase 2 - Laravel Reverb + real-time notifications

- Install laravel/reverb + laravel-echo + pusher-js
- Configure broadcasting to reverb in .env.example + .env
- Add Echo + Pusher client in resources/js/app.js
- Update all 14 notifications to implement ShouldBroadcast + broadcastOn()
- Update NotificationBell component to listen for real-time events
- Add Livewire.emit in notification-bell blade for JS-to-Livewire bridge

Tests: 101 passing (319 assertions)

app/Livewire/Common/NotificationBell.php

@@ -3,6 +3,7 @@
 namespace App\Livewire\Common;
 
 use Illuminate\Support\Facades\Auth;
+use Livewire\Attributes\On;
 use Livewire\Component;
 
 class NotificationBell extends Component
@@ -37,6 +38,13 @@ class NotificationBell extends Component
         $this->loadNotifications();
     }
 
+    #[On('notification-received')]
+    public function handleNotification($message = 'Nueva notificación')
+    {
+        $this->loadNotifications();
+        $this->dispatch('notify', $message);
+    }
+
     public function render()
     {
         return view('livewire.common.notification-bell');