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/domain/entities/stack.dart

@@ -0,0 +1,66 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'stack.freezed.dart';
+
+/// Container orchestration stack (Docker Compose stack).
+@freezed
+class Stack with _$Stack {
+  const factory Stack({
+    /// Unique stack identifier.
+    required String id,
+
+    /// Stack name.
+    required String name,
+
+    /// Stack type (compose, swarm, kubernetes).
+    @Default(StackType.compose) StackType type,
+
+    /// Current stack status.
+    @Default(StackStatus.unknown) StackStatus status,
+
+    /// Number of containers in the stack.
+    @Default(0) int containerCount,
+
+    /// Number of running containers.
+    @Default(0) int runningCount,
+
+    /// Path to the compose file (if applicable).
+    String? composeFile,
+
+    /// Environment name (e.g., production, staging).
+    String? environment,
+
+    /// When the stack was created.
+    DateTime? createdAt,
+
+    /// When the stack was last updated.
+    DateTime? updatedAt,
+  }) = _Stack;
+
+  const Stack._();
+
+  /// Whether all containers in the stack are running.
+  bool get isHealthy => runningCount == containerCount && containerCount > 0;
+
+  /// Whether the stack has any running containers.
+  bool get hasRunningContainers => runningCount > 0;
+
+  /// Whether the stack is partially running.
+  bool get isPartial =>
+      runningCount > 0 && runningCount < containerCount;
+}
+
+/// Stack orchestration type.
+enum StackType {
+  compose,
+  swarm,
+  kubernetes,
+}
+
+/// Stack status.
+enum StackStatus {
+  active,
+  inactive,
+  error,
+  unknown,
+}