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)

.env.example

@@ -33,7 +33,7 @@ SESSION_ENCRYPT=false
 SESSION_PATH=/
 SESSION_DOMAIN=null
 
-BROADCAST_CONNECTION=log
+BROADCAST_CONNECTION=reverb
 FILESYSTEM_DISK=local
 QUEUE_CONNECTION=redis
 
@@ -47,6 +47,13 @@ REDIS_HOST=127.0.0.1
 REDIS_PASSWORD=null
 REDIS_PORT=6379
 
+REVERB_APP_ID=1
+REVERB_APP_KEY=local
+REVERB_APP_SECRET=secret
+REVERB_HOST=127.0.0.1
+REVERB_PORT=8080
+REVERB_SCHEME=http
+
 MAIL_MAILER=log
 MAIL_SCHEME=null
 MAIL_HOST=127.0.0.1