feat: UI 系统中心化 + 趋势图重构 + 法律文档 H5 上线

- UI 系统: 新增 design_tokens / module_visuals / app_buttons / app_status_badge / app_toast / ai_content 六个共享模块; 28 个页面接入, SnackBar 全部替换为 AppToast
- 趋势图: 直线折线 + 渐变填充 + 阴影; 去网格线; X 轴日+月份分隔; Y 轴整数刻度最多 4 个; 点击数据点/录入记录显示上方浮层, 选中点变实心
- 法律文档 H5: 后端 wwwroot 托管隐私政策/服务协议/关于/个人信息收集清单/第三方 SDK 清单 + 索引页; Program.cs 启用 UseDefaultFiles + UseStaticFiles
- 其他: auth_provider 登录流程调整; api_client IP 适配; 主页智能体栏间距优化

health_app/lib/pages/history/conversation_history_page.dart

@@ -6,11 +6,8 @@ import '../../core/app_theme.dart';
 import '../../core/navigation_provider.dart';
 import '../../providers/chat_provider.dart';
 import '../../providers/conversation_history_provider.dart';
+import '../../widgets/app_toast.dart';
 
-/// 对话历史完整列表页。
-/// - 左滑删除（真删，删后 ScaffoldMessenger 提示）
-/// - 顶部"清空全部"按钮（确认弹窗 → 调 deleteAll）
-/// - 点击一条 → loadConversation → popRoute 回首页
 class ConversationHistoryPage extends ConsumerWidget {
   const ConversationHistoryPage({super.key});
 
@@ -21,7 +18,7 @@ class ConversationHistoryPage extends ConsumerWidget {
     return GradientScaffold(
       appBar: AppBar(
         backgroundColor: Colors.white.withValues(alpha: 0.9),
-        title: const Text('最近 7 次对话'),
+        title: const Text('对话记录'),
         leading: IconButton(
           icon: const Icon(Icons.arrow_back),
           onPressed: () => popRoute(ref),
@@ -82,18 +79,11 @@ class ConversationHistoryPage extends ConsumerWidget {
     try {
       await ref.read(conversationHistoryProvider.notifier).deleteOne(id);
       if (context.mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(content: Text('已删除'), duration: Duration(seconds: 1)),
-        );
+        AppToast.show(context, '已删除', type: AppToastType.success);
       }
     } catch (_) {
       if (context.mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(
-            content: Text('删除失败，请稍后重试'),
-            backgroundColor: AppColors.error,
-          ),
-        );
+        AppToast.show(context, '删除失败，请稍后重试', type: AppToastType.error);
       }
     }
   }
@@ -123,18 +113,11 @@ class ConversationHistoryPage extends ConsumerWidget {
           .read(conversationHistoryProvider.notifier)
           .clearAll();
       if (context.mounted) {
-        ScaffoldMessenger.of(
-          context,
-        ).showSnackBar(SnackBar(content: Text('已清空 $count 条对话')));
+        AppToast.show(context, '已清空 $count 条对话', type: AppToastType.success);
       }
     } catch (_) {
       if (context.mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(
-            content: Text('清空失败，请稍后重试'),
-            backgroundColor: AppColors.error,
-          ),
-        );
+        AppToast.show(context, '清空失败，请稍后重试', type: AppToastType.error);
       }
     }
   }
@@ -144,6 +127,7 @@ class _HistoryTile extends StatelessWidget {
   final ConversationListItem item;
   final VoidCallback onTap;
   final VoidCallback onDelete;
+
   const _HistoryTile({
     required this.item,
     required this.onTap,
@@ -157,25 +141,12 @@ class _HistoryTile extends StatelessWidget {
       direction: DismissDirection.endToStart,
       background: Container(
         alignment: Alignment.centerRight,
-        padding: const EdgeInsets.only(right: 22),
+        padding: const EdgeInsets.only(right: 18),
         decoration: BoxDecoration(
           color: AppColors.error,
           borderRadius: BorderRadius.circular(14),
         ),
-        child: const Row(
-          mainAxisSize: MainAxisSize.min,
-          children: [
-            Icon(Icons.delete_outline, color: Colors.white),
-            SizedBox(width: 6),
-            Text(
-              '删除',
-              style: TextStyle(
-                color: Colors.white,
-                fontWeight: FontWeight.w800,
-              ),
-            ),
-          ],
-        ),
+        child: const Icon(Icons.delete_outline, color: Colors.white),
       ),
       confirmDismiss: (_) async {
         onDelete();
@@ -185,7 +156,7 @@ class _HistoryTile extends StatelessWidget {
         onTap: onTap,
         borderRadius: BorderRadius.circular(14),
         child: Container(
-          padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
+          padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 14),
           decoration: BoxDecoration(
             color: Colors.white,
             borderRadius: BorderRadius.circular(14),
@@ -194,57 +165,25 @@ class _HistoryTile extends StatelessWidget {
           ),
           child: Row(
             children: [
-              Container(
-                width: 38,
-                height: 38,
-                decoration: BoxDecoration(
-                  color: const Color(0xFFEFF6FF),
-                  borderRadius: BorderRadius.circular(12),
-                ),
-                child: const Icon(
-                  Icons.forum_rounded,
-                  color: Color(0xFF2563EB),
-                  size: 20,
+              Expanded(
+                child: Text(
+                  _displaySummary(item),
+                  maxLines: 1,
+                  overflow: TextOverflow.ellipsis,
+                  style: const TextStyle(
+                    fontSize: 16,
+                    fontWeight: FontWeight.w800,
+                    color: AppColors.textPrimary,
+                  ),
                 ),
               ),
               const SizedBox(width: 12),
-              Expanded(
-                child: Column(
-                  crossAxisAlignment: CrossAxisAlignment.start,
-                  children: [
-                    Text(
-                      _displaySummary(item),
-                      maxLines: 2,
-                      overflow: TextOverflow.ellipsis,
-                      style: const TextStyle(
-                        fontSize: 15,
-                        fontWeight: FontWeight.w800,
-                        color: AppColors.textPrimary,
-                      ),
-                    ),
-                    const SizedBox(height: 3),
-                    if (_displayOriginalQuestion(item).isNotEmpty) ...[
-                      Text(
-                        '首问：${_displayOriginalQuestion(item)}',
-                        maxLines: 1,
-                        overflow: TextOverflow.ellipsis,
-                        style: const TextStyle(
-                          fontSize: 12,
-                          fontWeight: FontWeight.w600,
-                          color: AppColors.textHint,
-                        ),
-                      ),
-                      const SizedBox(height: 4),
-                    ],
-                    Text(
-                      '${item.messageCount} 条 · ${_relativeTime(item.updatedAt)}',
-                      style: const TextStyle(
-                        fontSize: 12,
-                        fontWeight: FontWeight.w600,
-                        color: AppColors.textHint,
-                      ),
-                    ),
-                  ],
+              Text(
+                _shortDate(item.updatedAt),
+                style: const TextStyle(
+                  fontSize: 14,
+                  fontWeight: FontWeight.w700,
+                  color: AppColors.textHint,
                 ),
               ),
             ],
@@ -254,39 +193,29 @@ class _HistoryTile extends StatelessWidget {
     );
   }
 
-  static String _displayTitle(ConversationListItem item) {
-    final s = item.summary?.trim();
-    if (s != null && s.isNotEmpty) return s;
-    final t = item.title?.trim();
-    if (t != null && t.isNotEmpty) return t;
-    return '未命名对话';
-  }
-
   static String _displaySummary(ConversationListItem item) {
     final s = item.summary?.trim();
     if (s != null && s.isNotEmpty) return s.replaceAll(RegExp(r'\s+'), ' ');
-    return _displayTitle(item);
-  }
-
-  static String _displayOriginalQuestion(ConversationListItem item) {
     final t = item.title?.trim();
-    if (t == null || t.isEmpty) return '';
-    final summary = item.summary?.trim();
-    if (summary != null && summary.isNotEmpty && summary != t) {
-      return t.replaceAll(RegExp(r'\s+'), ' ');
-    }
-    return '';
+    if (t != null && t.isNotEmpty) return t.replaceAll(RegExp(r'\s+'), ' ');
+    return '未命名对话';
   }
 
-  static String _relativeTime(DateTime time) {
+  static String _shortDate(DateTime time) {
     final now = DateTime.now();
     final local = time.toLocal();
-    final diff = now.difference(local);
-    if (diff.inMinutes < 1) return '刚刚';
-    if (diff.inHours < 1) return '${diff.inMinutes} 分钟前';
-    if (diff.inDays < 1) return '${diff.inHours} 小时前';
-    if (diff.inDays < 7) return '${diff.inDays} 天前';
-    return '${local.year}/${local.month}/${local.day}';
+    if (local.year == now.year &&
+        local.month == now.month &&
+        local.day == now.day) {
+      return '今天';
+    }
+    final yesterday = now.subtract(const Duration(days: 1));
+    if (local.year == yesterday.year &&
+        local.month == yesterday.month &&
+        local.day == yesterday.day) {
+      return '昨天';
+    }
+    return '${local.month}/${local.day}';
   }
 }
 
@@ -314,7 +243,7 @@ class _EmptyHint extends StatelessWidget {
               ),
               SizedBox(height: 6),
               Text(
-                '在首页和 AI 健康助手聊聊吧',
+                '在首页和 AI 健康助手聊天后会显示在这里',
                 style: TextStyle(fontSize: 13, color: AppColors.textSecondary),
               ),
             ],
@@ -328,6 +257,7 @@ class _EmptyHint extends StatelessWidget {
 class _ErrorBlock extends StatelessWidget {
   final String message;
   final VoidCallback onRetry;
+
   const _ErrorBlock({required this.message, required this.onRetry});
 
   @override