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/presentation/blocs/sequence/sequence_state.dart

@@ -0,0 +1,55 @@
+import '../../../domain/entities/sequence.dart';
+
+class SequenceState {
+  final List<SequenceDefinition> sequences;
+  final List<SequenceCategory> categories;
+  final Map<int, RunningSequence> running; // viewerId -> RunningSequence
+  final int? selectedCategoryId;
+  final bool isLoading;
+  final String? error;
+
+  const SequenceState({
+    this.sequences = const [],
+    this.categories = const [],
+    this.running = const {},
+    this.selectedCategoryId,
+    this.isLoading = false,
+    this.error,
+  });
+
+  /// Sequences filtered by selected category
+  List<SequenceDefinition> get filteredSequences {
+    if (selectedCategoryId == null) return sequences;
+    return sequences
+        .where((s) => s.categoryId == selectedCategoryId)
+        .toList();
+  }
+
+  /// Check if a sequence is running on a viewer
+  bool isRunningOnViewer(int viewerId) => running.containsKey(viewerId);
+
+  /// Get running sequence for a viewer
+  RunningSequence? getRunning(int viewerId) => running[viewerId];
+
+  SequenceState copyWith({
+    List<SequenceDefinition>? sequences,
+    List<SequenceCategory>? categories,
+    Map<int, RunningSequence>? running,
+    int? selectedCategoryId,
+    bool clearCategory = false,
+    bool? isLoading,
+    String? error,
+    bool clearError = false,
+  }) {
+    return SequenceState(
+      sequences: sequences ?? this.sequences,
+      categories: categories ?? this.categories,
+      running: running ?? this.running,
+      selectedCategoryId: clearCategory
+          ? null
+          : (selectedCategoryId ?? this.selectedCategoryId),
+      isLoading: isLoading ?? this.isLoading,
+      error: clearError ? null : (error ?? this.error),
+    );
+  }
+}