feat: add Control Room with containers and stacks management

- Add Control Room page with stacks sidebar and containers list
- Implement container actions (start/stop/restart) with snackbars
- Add container logs viewer dialog
- Add search/filter for both stacks and containers lists
- Add external links for Portainer and Netdata (url_launcher)
- Add VS Code launch configuration for Flutter web debugging

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lib/core/config/app_config.dart

@@ -58,4 +58,16 @@ class AppConfig {
   static bool get requiresAuth =>
       coreApiUrl.contains('schweitz.net') ||
       tatlockApiUrl.contains('schweitz.net');
+
+  /// Portainer URL for container management
+  static const portainerUrl = String.fromEnvironment(
+    'PORTAINER_URL',
+    defaultValue: 'http://192.168.86.149:9000',
+  );
+
+  /// Netdata URL for system monitoring
+  static const netdataUrl = String.fromEnvironment(
+    'NETDATA_URL',
+    defaultValue: 'http://192.168.86.149:19999',
+  );
 }