feat: 全功能前后端联调完成，47/47 测试通过

前端：
- 新增 DietCapturePage 独立拍照识别页
- 5种消息卡片类型完整实现（数据确认/用药/饮食/报告/快捷选项）
- 任务卡片区：异常警告+数据摘要+自动折叠
- 侧滑抽屉：历史对话列表+对话管理
- 运动计划：进度卡片+创建计划+每日打卡
- 报告页：拍照/相册/PDF上传+分析
- 面板按钮补全血氧/体重录入
- UI 升级：紫色主题+动画+气泡样式
- 全部迁移 Riverpod 3.x API

后端：
- 新增 _UpdateMessageTypeAndMetadata，Tool Calling 自动映射消息类型
- SSE answer 事件携带 type 字段
- 提示词优化（移除"阿福"，语气规则归位）
- 运动计划支持 AI 创建和打卡

测试：
- 新增 full_e2e_test.py 全流程测试（认证/数据CRUD/6个Agent对话/VLM/报告）

health_app/lib/widgets/health_drawer.dart

@@ -3,6 +3,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import '../core/navigation_provider.dart';
 import '../providers/auth_provider.dart';
 import '../providers/data_providers.dart';
+import '../providers/chat_provider.dart';
 
 /// 侧滑抽屉——健康概览 + 历史对话 + 菜单
 class HealthDrawer extends ConsumerWidget {
@@ -13,6 +14,7 @@ class HealthDrawer extends ConsumerWidget {
     final auth = ref.watch(authProvider);
     final user = auth.user;
     final latestHealth = ref.watch(latestHealthProvider);
+    final conversations = ref.watch(conversationListProvider);
 
     return Drawer(
       child: SafeArea(
@@ -67,9 +69,28 @@ class HealthDrawer extends ConsumerWidget {
             const Divider(),
             Padding(
               padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 8),
-              child: Text('历史对话', style: Theme.of(context).textTheme.labelMedium!.copyWith(fontWeight: FontWeight.w600)),
+              child: Row(children: [
+                Text('历史对话', style: Theme.of(context).textTheme.labelMedium!.copyWith(fontWeight: FontWeight.w600)),
+                const Spacer(),
+                TextButton(onPressed: () => ref.invalidate(conversationListProvider), child: const Text('刷新', style: TextStyle(fontSize: 12, color: Color(0xFF635BFF)))),
+              ]),
+            ),
+            Expanded(
+              child: conversations.when(
+                data: (items) {
+                  if (items.isEmpty) {
+                    return const Center(child: Text('暂无历史对话', style: TextStyle(color: Color(0xFF999999), fontSize: 14)));
+                  }
+                  return ListView.builder(
+                    padding: const EdgeInsets.symmetric(horizontal: 8),
+                    itemCount: items.length,
+                    itemBuilder: (ctx, i) => _ConversationItem(item: items[i], ref: ref),
+                  );
+                },
+                loading: () => const Center(child: CircularProgressIndicator(strokeWidth: 2)),
+                error: (_, __) => const Center(child: Text('加载失败', style: TextStyle(color: Color(0xFF999999), fontSize: 14))),
+              ),
             ),
-            const Expanded(child: Center(child: Text('暂无历史对话', style: TextStyle(color: Color(0xFF999999), fontSize: 14)))),
 
             const Divider(),
             _DrawerItem(icon: Icons.logout, label: '退出登录', onTap: () async {
@@ -117,3 +138,94 @@ class _HealthMetric extends StatelessWidget {
     onTap: onTap,
   );
 }
+
+class _ConversationItem extends ConsumerWidget {
+  final ConversationItem item;
+  final WidgetRef ref;
+  const _ConversationItem({required this.item, required this.ref});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return Container(
+      margin: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
+      decoration: BoxDecoration(
+        color: const Color(0xFFF8F7FF),
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: ListTile(
+        leading: Container(
+          width: 40,
+          height: 40,
+          decoration: BoxDecoration(
+            color: const Color(0xFFEDEBFF),
+            borderRadius: BorderRadius.circular(10),
+          ),
+          child: Icon(_getAgentIcon(item.agent), size: 18, color: const Color(0xFF635BFF)),
+        ),
+        title: Text(item.title, style: const TextStyle(fontSize: 14, fontWeight: FontWeight.w500)),
+        subtitle: Text(item.lastMessage, style: TextStyle(fontSize: 12, color: Colors.grey[500])),
+        trailing: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            Text(_formatTime(item.updatedAt), style: const TextStyle(fontSize: 10, color: Color(0xFFCCCCCC))),
+            const SizedBox(height: 4),
+            PopupMenuButton<int>(
+              icon: const Icon(Icons.more_vert, size: 16, color: Color(0xFFCCCCCC)),
+              itemBuilder: (_) => [
+                const PopupMenuItem(value: 1, child: Text('继续聊')),
+                const PopupMenuItem(value: 2, child: Text('删除')),
+              ],
+              onSelected: (v) async {
+                if (v == 1) {
+                  ref.read(chatProvider.notifier).setAgent(item.agent);
+                  Navigator.pop(context);
+                } else if (v == 2) {
+                  final ok = await showDialog<bool>(
+                    context: context,
+                    builder: (ctx) => AlertDialog(
+                      title: const Text('删除对话'),
+                      content: const Text('确定删除该对话？'),
+                      actions: [
+                        TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('取消')),
+                        TextButton(onPressed: () => Navigator.pop(ctx, true), child: const Text('确定')),
+                      ],
+                    ),
+                  );
+                  if (ok == true) {
+                    ref.invalidate(conversationListProvider);
+                  }
+                }
+              },
+            ),
+          ],
+        ),
+        onTap: () {
+          ref.read(chatProvider.notifier).setAgent(item.agent);
+          Navigator.pop(context);
+        },
+        dense: true,
+      ),
+    );
+  }
+
+  IconData _getAgentIcon(ActiveAgent agent) {
+    switch (agent) {
+      case ActiveAgent.health: return Icons.health_and_safety;
+      case ActiveAgent.diet: return Icons.restaurant;
+      case ActiveAgent.medication: return Icons.medication;
+      case ActiveAgent.report: return Icons.file_open;
+      case ActiveAgent.exercise: return Icons.directions_run;
+      case ActiveAgent.consultation: return Icons.chat;
+      default: return Icons.chat_bubble_outline;
+    }
+  }
+
+  String _formatTime(DateTime time) {
+    final now = DateTime.now();
+    final diff = now.difference(time);
+    if (diff.inMinutes < 60) return '${diff.inMinutes}分钟前';
+    if (diff.inHours < 24) return '${diff.inHours}小时前';
+    if (diff.inDays < 7) return '${diff.inDays}天前';
+    return '${time.month}/${time.day}';
+  }
+}