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)

package.json

@@ -13,8 +13,10 @@
         "axios": "^1.11.0",
         "concurrently": "^9.0.1",
         "daisyui": "^5.5.19",
+        "laravel-echo": "^2.4.0",
         "laravel-vite-plugin": "^2.0.0",
         "postcss": "^8.5.12",
+        "pusher-js": "^8.6.0",
         "tailwindcss": "^3.4.19",
         "vite": "^7.0.7"
     },