feat: implement actual webhook delivery

Implement full webhook delivery functionality:
- Create SendWebhookJob to handle HTTP POST requests
- Update WebhookChannel to dispatch webhook jobs
- Configure retry logic (5 attempts, 10s backoff)
- Update Test notification payload with success/message structure

Webhook payload structure:
{
  "success": true/false,
  "message": "notification message",
  "event": "event_type",
  "url": "coolify_dashboard_url"
}

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

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

app/Notifications/Channels/WebhookChannel.php

@@ -2,8 +2,8 @@
 
 namespace App\Notifications\Channels;
 
+use App\Jobs\SendWebhookJob;
 use Illuminate\Notifications\Notification;
-use Illuminate\Support\Facades\Log;
 
 class WebhookChannel
 {
@@ -18,16 +18,8 @@ class WebhookChannel
             return;
         }
 
-        // TODO: Implement actual webhook delivery
-        // This is a placeholder implementation
-        // You'll need to:
-        // 1. Get the webhook payload from $notification->toWebhook()
-        // 2. Create a job to send the HTTP POST request to $webhookSettings->webhook_url
-        // 3. Handle retries and errors appropriately
+        $payload = $notification->toWebhook();
 
-        Log::info('Webhook notification would be sent', [
-            'url' => $webhookSettings->webhook_url,
-            'notification' => get_class($notification),
-        ]);
+        SendWebhookJob::dispatch($payload, $webhookSettings->webhook_url);
     }
 }