feat: add UUIDs and URLs to webhook notifications

- Add resource UUIDs (application_uuid, database_uuid, server_uuid, task_uuid) to all webhook notifications
- Standardize URL field naming from various formats (resource_url, task_url, server_url) to consistent 'url' field
- Include parent resource UUIDs for scheduled tasks (application_uuid or service_uuid)
- Add direct URLs to Coolify resources for all notification types
- Update UI to show "Webhook URL (POST)" label for clarity

This enables webhook consumers to:
- Uniquely identify resources using UUIDs used throughout Coolify UI
- Directly link back to Coolify resource pages via the url field

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

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

app/Notifications/Server/Unreachable.php

@@ -82,4 +82,18 @@ class Unreachable extends CustomEmailNotification
             color: SlackMessage::errorColor()
         );
     }
+
+    public function toWebhook(): array
+    {
+        $url = base_url().'/server/'.$this->server->uuid;
+
+        return [
+            'success' => false,
+            'message' => 'Server unreachable',
+            'event' => 'server_unreachable',
+            'server_name' => $this->server->name,
+            'server_uuid' => $this->server->uuid,
+            'url' => $url,
+        ];
+    }
 }