feat: add custom webhook notification support

Add basic infrastructure for custom webhook notifications:
- Create webhook_notification_settings table with event toggles
- Add WebhookNotificationSettings model with encrypted URL
- Integrate webhook settings into Team model and HasNotificationSettings trait
- Create Livewire component and Blade view for webhook configuration
- Add webhook navigation route and UI

This provides the foundation for sending webhook notifications to custom HTTP/HTTPS endpoints when events occur in Coolify.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/Traits/HasNotificationSettings.php

@@ -30,6 +30,7 @@ trait HasNotificationSettings
             'telegram' => $this->telegramNotificationSettings,
             'slack' => $this->slackNotificationSettings,
             'pushover' => $this->pushoverNotificationSettings,
+            'webhook' => $this->webhookNotificationSettings,
             default => null,
         };
     }