refactor(apps): 主题系统迁移至 ColorScheme + 扩展架构并支持 Dark Mode

apps/lib/features/chat/presentation/bloc/agent_stage.dart

@@ -1,25 +0,0 @@
-import '../../../../core/l10n/l10n.dart';
-
-enum AgentStage { routing, execution, memory }
-
-AgentStage? stageFromStepName(String value) {
-  switch (value) {
-    case 'router':
-      return AgentStage.routing;
-    case 'worker':
-      return AgentStage.execution;
-    case 'memory':
-      return AgentStage.memory;
-    default:
-      return null;
-  }
-}
-
-String stageLabel(AgentStage? stage) {
-  return switch (stage) {
-    AgentStage.routing => L10n.current.agentStageRouting,
-    AgentStage.execution => L10n.current.agentStageExecution,
-    AgentStage.memory => L10n.current.agentStageMemory,
-    null => L10n.current.agentStageProcessing,
-  };
-}

apps/lib/features/chat/presentation/bloc/chat_bloc.dart

@@ -2,25 +2,37 @@ import 'dart:typed_data';
 
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:image_picker/image_picker.dart';
+import 'package:social_app/core/chat/agent_stage.dart';
+import 'package:social_app/core/chat/chat_list_item.dart';
+import 'package:social_app/core/chat/chat_orchestrator.dart';
 import 'package:social_app/core/network/i_api_client.dart';
 import 'package:social_app/core/l10n/l10n.dart';
 
 import '../../data/models/ag_ui_event.dart';
-import '../../data/models/chat_list_item.dart';
 import '../../data/services/ag_ui_service.dart';
-import 'agent_stage.dart';
 
-class ChatState {
+class ChatState implements ChatOrchestratorState {
+  @override
   final List<ChatListItem> items;
+  @override
   final bool isSending;
+  @override
   final bool isWaitingFirstToken;
+  @override
   final bool isStreaming;
+  @override
   final bool isCancelling;
+  @override
   final bool isLoadingHistory;
+  @override
   final String? currentMessageId;
+  @override
   final String? error;
+  @override
   final DateTime? oldestLoadedDate;
+  @override
   final bool hasEarlierHistory;
+  @override
   final AgentStage? currentStage;
 
   const ChatState({
@@ -37,6 +49,7 @@ class ChatState {
     this.currentStage,
   });
 
+  @override
   bool get isLoading =>
       isSending ||
       isWaitingFirstToken ||
@@ -81,7 +94,7 @@ class ChatState {
   }
 }
 
-class ChatBloc extends Cubit<ChatState> {
+class ChatBloc extends Cubit<ChatState> implements ChatOrchestrator {
   ChatBloc({AgUiService? service, required IApiClient apiClient})
     : _service = service ?? AgUiService(apiClient: apiClient),
       super(const ChatState()) {
@@ -382,6 +395,7 @@ class ChatBloc extends Cubit<ChatState> {
         .reduce((a, b) => a.isBefore(b) ? a : b);
   }
 
+  @override
   Future<void> sendMessage(String content, {List<XFile>? images}) async {
     final messageId = 'user-${DateTime.now().millisecondsSinceEpoch}';
     final attachments = (images ?? const <XFile>[])
@@ -527,6 +541,7 @@ class ChatBloc extends Cubit<ChatState> {
     emit(state.copyWith(items: items));
   }
 
+  @override
   Future<void> loadHistory() async {
     if (state.isLoadingHistory) return;
     emit(state.copyWith(isLoadingHistory: true));
@@ -554,6 +569,7 @@ class ChatBloc extends Cubit<ChatState> {
     }
   }
 
+  @override
   Future<void> loadMoreHistory() async {
     if (state.isLoadingHistory || !state.hasEarlierHistory) return;
     if (state.oldestLoadedDate == null) return;
@@ -584,10 +600,12 @@ class ChatBloc extends Cubit<ChatState> {
     }
   }
 
+  @override
   Future<String> transcribeAudioFile(String filePath) {
     return _service.transcribeAudio(filePath);
   }
 
+  @override
   Future<bool> cancelCurrentRun() async {
     if (!(state.isWaitingFirstToken ||
         state.isStreaming ||
@@ -637,6 +655,7 @@ class ChatBloc extends Cubit<ChatState> {
     return future;
   }
 
+  @override
   void clearError() {
     emit(state.copyWith(error: null));
   }