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/Container/ContainerStopped.php

@@ -102,4 +102,22 @@ class ContainerStopped extends CustomEmailNotification
             color: SlackMessage::errorColor()
         );
     }
+
+    public function toWebhook(): array
+    {
+        $data = [
+            'success' => false,
+            'message' => 'Resource stopped unexpectedly',
+            'event' => 'container_stopped',
+            'container_name' => $this->name,
+            'server_name' => $this->server->name,
+            'server_uuid' => $this->server->uuid,
+        ];
+
+        if ($this->url) {
+            $data['url'] = $this->url;
+        }
+
+        return $data;
+    }
 }