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/features/control_room/stacks/presentation/providers/stacks_provider.dart

@@ -0,0 +1,35 @@
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+import '../../data/repositories/stack_repository_impl.dart';
+import '../../domain/entities/stack.dart';
+
+part 'stacks_provider.g.dart';
+
+/// Provides the list of all stacks.
+@riverpod
+Future<List<Stack>> stacks(StacksRef ref) async {
+  final repository = ref.watch(stackRepositoryProvider);
+  return repository.getStacks();
+}
+
+/// Provides a single stack by ID.
+@riverpod
+Future<Stack> stack(StackRef ref, String id) async {
+  final repository = ref.watch(stackRepositoryProvider);
+  return repository.getStack(id);
+}
+
+/// Currently selected stack ID (null = all containers).
+@riverpod
+class SelectedStack extends _$SelectedStack {
+  @override
+  String? build() => null;
+
+  void select(String? stackId) {
+    state = stackId;
+  }
+
+  void clear() {
+    state = null;
+  }
+}