refactor(chat): 重构聊天模块并集成历史消息加载功能

- 删除冗余的 chat_history_repository 和 home_mock_data
- 简化 ag_ui_event fromJson 使用工厂映射表
- 提取 ChatBloc 事件处理方法，添加 loadHistory/loadMoreHistory
- HomeScreen 集成 ChatBloc 实现历史消息加载和下拉刷新
- 更新 AGENTS.md 文档约束

apps/lib/features/home/data/home_mock_data.dart

@@ -1,295 +0,0 @@
-import 'package:flutter/material.dart';
-import '../../../shared/widgets/chat_bubble.dart';
-
-enum ChatItemType { message, schedule }
-
-abstract class ChatListItem {
-  String get id;
-  DateTime get timestamp;
-  ChatItemType get type;
-  MessageSender get sender;
-}
-
-class HomeMockData {
-  static List<ChatListItem> getTodayItems() {
-    final now = DateTime.now();
-    final today = DateTime(now.year, now.month, now.day);
-    return _getMockItems().where((item) {
-      final itemDate = DateTime(
-        item.timestamp.year,
-        item.timestamp.month,
-        item.timestamp.day,
-      );
-      return itemDate == today;
-    }).toList();
-  }
-
-  static Future<List<ChatListItem>> loadMoreItems(DateTime beforeDate) async {
-    return _getOlderMockItems(beforeDate);
-  }
-
-  static List<ChatListItem> _getMockItems() {
-    final now = DateTime.now();
-    final today = DateTime(now.year, now.month, now.day);
-    final todayStart = DateTime(today.year, today.month, today.day);
-
-    return [
-      ChatMessageItem(
-        id: 'm4',
-        content: '明天提醒我开会',
-        timestamp: todayStart.add(const Duration(hours: 14)),
-        sender: MessageSender.user,
-      ),
-      ScheduleItemWrapper(
-        id: 's1',
-        scheduleItem: ScheduleItemModel(
-          id: 's1',
-          title: '产品评审会议',
-          description: '讨论Q2产品路线图',
-          startAt: todayStart.add(const Duration(days: 1, hours: 10)),
-          endAt: todayStart.add(const Duration(days: 1, hours: 11)),
-          timezone: 'Asia/Shanghai',
-          sourceType: ScheduleSourceType.agentGenerated,
-          status: ScheduleStatus.active,
-          metadata: ScheduleMetadata(
-            color: '#4F46E5',
-            location: '会议室A / 在线',
-            notes: '需要提前准备Q2数据',
-            attachments: [
-              Attachment(
-                name: 'Q2路线图.pdf',
-                type: AttachmentType.document,
-                url: 'https://example.com/q2.pdf',
-              ),
-            ],
-          ),
-          createdAt: todayStart.subtract(const Duration(hours: 5)),
-        ),
-        timestamp: todayStart.add(const Duration(hours: 14, minutes: 2)),
-        sender: MessageSender.ai,
-      ),
-      ChatMessageItem(
-        id: 'm5',
-        content: '已为你创建日程"产品评审会议"，明天上午10:00。我还会提前15分钟提醒你。',
-        timestamp: todayStart.add(const Duration(hours: 14, minutes: 2)),
-        sender: MessageSender.ai,
-      ),
-    ];
-  }
-
-  static List<ChatListItem> _getOlderMockItems(DateTime beforeDate) {
-    final before = DateTime(beforeDate.year, beforeDate.month, beforeDate.day);
-    final dayBefore = before.subtract(const Duration(days: 1));
-
-    return [
-      ChatMessageItem(
-        id: 'm1',
-        content: '你好，我有什么可以帮你的？',
-        timestamp: dayBefore.add(const Duration(hours: 10)),
-        sender: MessageSender.ai,
-      ),
-      ChatMessageItem(
-        id: 'm2',
-        content: '下周一之前提交项目报告',
-        timestamp: dayBefore.add(const Duration(hours: 9, minutes: 55)),
-        sender: MessageSender.user,
-      ),
-      ScheduleItemWrapper(
-        id: 's0',
-        scheduleItem: ScheduleItemModel(
-          id: 's0',
-          title: '提交项目报告',
-          description: '完成并提交Q2项目报告',
-          startAt: before.subtract(const Duration(days: 3)),
-          endAt: null,
-          timezone: 'Asia/Shanghai',
-          sourceType: ScheduleSourceType.agentGenerated,
-          status: ScheduleStatus.active,
-          metadata: ScheduleMetadata(
-            color: '#F59E0B',
-            location: null,
-            notes: '记得附上数据附件',
-            attachments: [],
-          ),
-          createdAt: dayBefore.add(const Duration(hours: 9, minutes: 50)),
-        ),
-        timestamp: dayBefore.add(const Duration(hours: 9, minutes: 50)),
-        sender: MessageSender.ai,
-      ),
-      ChatMessageItem(
-        id: 'm3',
-        content: '好的，我已帮你创建待办事项"提交项目报告"，截止日期为下周一。我还会提醒你完成这项任务。',
-        timestamp: dayBefore.add(const Duration(hours: 9, minutes: 50)),
-        sender: MessageSender.ai,
-      ),
-    ];
-  }
-}
-
-class ChatMessageItem extends ChatListItem {
-  @override
-  final String id;
-  final String content;
-  @override
-  final DateTime timestamp;
-  @override
-  final MessageSender sender;
-
-  ChatMessageItem({
-    required this.id,
-    required this.content,
-    required this.timestamp,
-    required this.sender,
-  });
-
-  @override
-  ChatItemType get type => ChatItemType.message;
-}
-
-class ScheduleItemWrapper extends ChatListItem {
-  @override
-  final String id;
-  final ScheduleItemModel scheduleItem;
-  @override
-  final DateTime timestamp;
-  @override
-  final MessageSender sender;
-
-  ScheduleItemWrapper({
-    required this.id,
-    required this.scheduleItem,
-    required this.timestamp,
-    required this.sender,
-  });
-
-  @override
-  ChatItemType get type => ChatItemType.schedule;
-}
-
-enum ScheduleSourceType { manual, imported, agentGenerated }
-
-enum ScheduleStatus { active, completed, canceled, archived }
-
-class ScheduleItemModel {
-  final String id;
-  final String title;
-  final String? description;
-  final DateTime startAt;
-  final DateTime? endAt;
-  final String timezone;
-  final ScheduleSourceType sourceType;
-  final ScheduleStatus status;
-  final ScheduleMetadata? metadata;
-  final DateTime createdAt;
-
-  ScheduleItemModel({
-    required this.id,
-    required this.title,
-    this.description,
-    required this.startAt,
-    this.endAt,
-    required this.timezone,
-    required this.sourceType,
-    required this.status,
-    this.metadata,
-    required this.createdAt,
-  });
-
-  factory ScheduleItemModel.fromJson(Map<String, dynamic> json) {
-    return ScheduleItemModel(
-      id: json['id'],
-      title: json['title'],
-      description: json['description'],
-      startAt: DateTime.parse(json['start_at']),
-      endAt: json['end_at'] != null ? DateTime.parse(json['end_at']) : null,
-      timezone: json['timezone'] ?? 'UTC',
-      sourceType: ScheduleSourceType.values.firstWhere(
-        (e) => e.name == json['source_type'],
-        orElse: () => ScheduleSourceType.manual,
-      ),
-      status: ScheduleStatus.values.firstWhere(
-        (e) => e.name == json['status'],
-        orElse: () => ScheduleStatus.active,
-      ),
-      metadata: json['metadata'] != null
-          ? ScheduleMetadata(
-              color: json['metadata']['color'],
-              location: json['metadata']['location'],
-              notes: json['metadata']['notes'],
-              attachments:
-                  (json['metadata']['attachments'] as List<dynamic>?)
-                      ?.map(
-                        (a) => Attachment(
-                          name: a['name'],
-                          type: a['type'] == 'document'
-                              ? AttachmentType.document
-                              : AttachmentType.reminder,
-                          url: a['url'],
-                          content: a['content'],
-                          note: a['note'],
-                        ),
-                      )
-                      .toList() ??
-                  [],
-            )
-          : null,
-      createdAt: DateTime.parse(json['created_at']),
-    );
-  }
-}
-
-class ScheduleMetadata {
-  final String? color;
-  final String? location;
-  final String? notes;
-  final List<Attachment> attachments;
-
-  ScheduleMetadata({
-    this.color,
-    this.location,
-    this.notes,
-    this.attachments = const [],
-  });
-}
-
-enum AttachmentType { document, reminder }
-
-class Attachment {
-  final String name;
-  final AttachmentType type;
-  final String? url;
-  final String? content;
-  final String? note;
-
-  Attachment({
-    required this.name,
-    required this.type,
-    this.url,
-    this.content,
-    this.note,
-  });
-}
-
-extension ScheduleSourceTypeExtension on ScheduleSourceType {
-  String get displayName {
-    switch (this) {
-      case ScheduleSourceType.manual:
-        return '手动创建';
-      case ScheduleSourceType.imported:
-        return '导入';
-      case ScheduleSourceType.agentGenerated:
-        return 'AI生成';
-    }
-  }
-
-  IconData get icon {
-    switch (this) {
-      case ScheduleSourceType.manual:
-        return Icons.edit_calendar;
-      case ScheduleSourceType.imported:
-        return Icons.download;
-      case ScheduleSourceType.agentGenerated:
-        return Icons.auto_awesome;
-    }
-  }
-}

apps/lib/features/home/ui/screens/home_screen.dart

@@ -16,8 +16,6 @@ const _defaultPadding = 20.0;
 const _itemSpacing = 16.0;
 const _inputPadding = 16.0;
 const _iconSize = 24.0;
-const _avatarSize = 32.0;
-const _botIconSize = 18.0;
 const _messagePaddingH = 13.0;
 const _messagePaddingV = 9.0;
 const _cornerRadius = 12.0;
@@ -39,6 +37,7 @@ class HomeScreen extends StatefulWidget {
 class _HomeScreenState extends State<HomeScreen> {
   final TextEditingController _messageController = TextEditingController();
   final ScrollController _scrollController = ScrollController();
+  late final ChatBloc _chatBloc;
 
   bool get _hasMessage => _messageController.text.trim().isNotEmpty;
 
@@ -46,6 +45,8 @@ class _HomeScreenState extends State<HomeScreen> {
   void initState() {
     super.initState();
     _messageController.addListener(_onMessageChanged);
+    _chatBloc = ChatBloc();
+    _chatBloc.loadHistory();
   }
 
   @override
@@ -53,6 +54,7 @@ class _HomeScreenState extends State<HomeScreen> {
     _messageController.removeListener(_onMessageChanged);
     _messageController.dispose();
     _scrollController.dispose();
+    _chatBloc.close();
     super.dispose();
   }
 
@@ -62,8 +64,8 @@ class _HomeScreenState extends State<HomeScreen> {
 
   @override
   Widget build(BuildContext context) {
-    return BlocProvider(
-      create: (context) => ChatBloc(),
+    return BlocProvider.value(
+      value: _chatBloc,
       child: BlocConsumer<ChatBloc, ChatState>(
         listener: (context, state) {
           if (state.error != null) {
@@ -132,6 +134,10 @@ class _HomeScreenState extends State<HomeScreen> {
   }
 
   Widget _buildChatArea(BuildContext context, ChatState state) {
+    if (state.isLoading && state.items.isEmpty) {
+      return const Center(child: CircularProgressIndicator());
+    }
+
     if (state.items.isEmpty) {
       return const Center(
         child: Text(
@@ -141,30 +147,96 @@ class _HomeScreenState extends State<HomeScreen> {
       );
     }
 
-    WidgetsBinding.instance.addPostFrameCallback((_) {
-      if (_scrollController.hasClients) {
-        _scrollController.animateTo(
-          _scrollController.position.maxScrollExtent,
-          duration: const Duration(milliseconds: _scrollDurationMs),
-          curve: Curves.easeOut,
-        );
-      }
-    });
+    return RefreshIndicator(
+      onRefresh: () => _onRefresh(context),
+      child: ListView.builder(
+        controller: _scrollController,
+        physics: const AlwaysScrollableScrollPhysics(),
+        padding: const EdgeInsets.all(_defaultPadding),
+        itemCount: state.items.length + (state.hasEarlierHistory ? 1 : 0),
+        itemBuilder: (context, index) {
+          if (index == 0 && state.hasEarlierHistory) {
+            return _buildLoadMoreButton(context, state.isLoading);
+          }
 
-    return ListView.builder(
-      controller: _scrollController,
-      padding: const EdgeInsets.all(_defaultPadding),
-      itemCount: state.items.length,
-      itemBuilder: (context, index) {
-        final item = state.items[index];
-        return Padding(
-          padding: const EdgeInsets.only(bottom: _itemSpacing),
-          child: _buildChatItem(item),
-        );
-      },
+          final itemIndex = state.hasEarlierHistory ? index - 1 : index;
+          final item = state.items[itemIndex];
+
+          final showDateDivider =
+              itemIndex == 0 ||
+              !_isSameDay(state.items[itemIndex - 1].timestamp, item.timestamp);
+
+          return Column(
+            crossAxisAlignment: CrossAxisAlignment.stretch,
+            children: [
+              if (showDateDivider) _buildDateDivider(item.timestamp),
+              Padding(
+                padding: const EdgeInsets.only(bottom: _itemSpacing),
+                child: _buildChatItem(item),
+              ),
+            ],
+          );
+        },
+      ),
     );
   }
 
+  bool _isSameDay(DateTime a, DateTime b) {
+    return a.year == b.year && a.month == b.month && a.day == b.day;
+  }
+
+  Widget _buildDateDivider(DateTime date) {
+    final now = DateTime.now();
+    final weekdays = ['周一', '周二', '周三', '周四', '周五', '周六', '周日'];
+    final weekday = weekdays[date.weekday - 1];
+
+    // For all dates (today/yesterday/this year), use the same format
+    // Only add year prefix for dates from previous years
+    final label = date.year == now.year
+        ? '${date.month}月${date.day}日 $weekday'
+        : '${date.year}年${date.month}月${date.day}日 $weekday';
+
+    return Container(
+      padding: const EdgeInsets.symmetric(vertical: 12),
+      alignment: Alignment.center,
+      child: Text(
+        label,
+        style: const TextStyle(fontSize: 12, color: AppColors.slate400),
+      ),
+    );
+  }
+
+  Widget _buildLoadMoreButton(BuildContext context, bool isLoading) {
+    return GestureDetector(
+      onTap: isLoading ? null : () => _onLoadMore(context),
+      child: Container(
+        padding: const EdgeInsets.symmetric(vertical: 8),
+        alignment: Alignment.center,
+        child: isLoading
+            ? const SizedBox(
+                width: 14,
+                height: 14,
+                child: CircularProgressIndicator(
+                  strokeWidth: 1.5,
+                  color: AppColors.slate400,
+                ),
+              )
+            : const Text(
+                '查看历史',
+                style: TextStyle(fontSize: 12, color: AppColors.slate400),
+              ),
+      ),
+    );
+  }
+
+  Future<void> _onRefresh(BuildContext context) async {
+    await context.read<ChatBloc>().loadMoreHistory();
+  }
+
+  void _onLoadMore(BuildContext context) {
+    context.read<ChatBloc>().loadMoreHistory();
+  }
+
   Widget _buildChatItem(ChatListItem item) {
     switch (item.type) {
       case ChatItemType.message:
@@ -182,24 +254,8 @@ class _HomeScreenState extends State<HomeScreen> {
       mainAxisAlignment: isUser
           ? MainAxisAlignment.end
           : MainAxisAlignment.start,
-      crossAxisAlignment: CrossAxisAlignment.center,
+      crossAxisAlignment: CrossAxisAlignment.start,
       children: [
-        if (!isUser) ...[
-          Container(
-            width: _avatarSize,
-            height: _avatarSize,
-            decoration: BoxDecoration(
-              color: AppColors.blue100,
-              shape: BoxShape.circle,
-            ),
-            child: const Icon(
-              LucideIcons.bot,
-              size: _botIconSize,
-              color: AppColors.blue600,
-            ),
-          ),
-          const SizedBox(width: 8),
-        ],
         Flexible(
           child: Container(
             padding: const EdgeInsets.symmetric(
@@ -222,8 +278,6 @@ class _HomeScreenState extends State<HomeScreen> {
             ),
           ),
         ),
-        if (isUser) const SizedBox(width: 40),
-        if (!isUser) const SizedBox(width: 40),
       ],
     );
   }
@@ -365,6 +419,16 @@ class _HomeScreenState extends State<HomeScreen> {
     if (content.isEmpty) return;
     _messageController.clear();
     context.read<ChatBloc>().sendMessage(content);
+
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (_scrollController.hasClients) {
+        _scrollController.animateTo(
+          _scrollController.position.maxScrollExtent,
+          duration: const Duration(milliseconds: _scrollDurationMs),
+          curve: Curves.easeOut,
+        );
+      }
+    });
   }
 
   void _showBottomSheet(BuildContext context) {