Initial commit: COPILOT D6 Flutter keyboard controller

Flutter web app replacing legacy WPF CCTV surveillance keyboard controller.
Includes wall overview, section view with monitor grid, camera input,
PTZ control, alarm/lock/sequence BLoCs, and legacy-matching UI styling.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

copilot_keyboard/lib/data/services/function_button_service.dart

@@ -0,0 +1,67 @@
+import 'package:logger/logger.dart';
+
+import '../../domain/entities/function_button_config.dart';
+import 'bridge_service.dart';
+import 'coordination_service.dart';
+
+/// Executes function button actions (F1-F7).
+/// Ported from legacy FunctionButtonsService.cs.
+class FunctionButtonService {
+  final BridgeService _bridgeService;
+  final CoordinationService _coordinationService;
+  final Logger _logger = Logger();
+
+  FunctionButtonConfig _config = const FunctionButtonConfig();
+
+  FunctionButtonService({
+    required BridgeService bridgeService,
+    required CoordinationService coordinationService,
+  })  : _bridgeService = bridgeService,
+        _coordinationService = coordinationService;
+
+  /// Load function button configuration.
+  void loadConfig(FunctionButtonConfig config) {
+    _config = config;
+    _logger.i('Loaded function button config: ${config.walls.length} walls');
+  }
+
+  /// Execute all actions for a button on a specific wall.
+  /// Actions are executed sequentially (like legacy).
+  Future<bool> execute(String wallId, String buttonKey) async {
+    final actions = _config.getActions(wallId, buttonKey);
+    if (actions.isEmpty) {
+      _logger.d('No actions for $buttonKey on wall $wallId');
+      return false;
+    }
+
+    _logger.i('Executing $buttonKey on wall $wallId (${actions.length} actions)');
+
+    for (final action in actions) {
+      try {
+        switch (action.type) {
+          case FunctionButtonActionType.crossSwitch:
+            await _bridgeService.viewerConnectLive(
+                action.viewerId, action.sourceId);
+            _logger.d(
+                'CrossSwitch: viewer ${action.viewerId} -> camera ${action.sourceId}');
+
+          case FunctionButtonActionType.sequenceStart:
+            await _coordinationService.startSequence(
+                action.viewerId, action.sourceId);
+            _logger.d(
+                'SequenceStart: viewer ${action.viewerId} -> sequence ${action.sourceId}');
+        }
+      } catch (e) {
+        _logger.e(
+            'Function button action failed: ${action.type.name} - $e');
+      }
+    }
+
+    return true;
+  }
+
+  /// Check if a button has actions for a given wall.
+  bool hasActions(String wallId, String buttonKey) {
+    return _config.hasActions(wallId, buttonKey);
+  }
+}