refactor: 死代码清理 + 趋势图重构 + 侧边栏交互优化 + 智能体卡片去延迟

- 死代码清理: 删除 AppCard/AppMenuItem/AppTabChip/AppButtons 等 4 个未使用 Widget 文件; 清理 common_widgets/enterprise_widgets/app_status_badge 中未使用 class; 移除 HealthService 等未使用方法; 后端移除 ExerciseService.CreateFromItemsAsync/HealthArchiveService.GetOrCreateAsync/MedicationAgentHandler 死分支/ChatRequest DTO
- 趋势图: 直线折线 + 渐变填充 + 阴影; 去网格; X 轴日+月份; 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
- 侧边栏: 对话记录改单选删除(灰底高亮); 操作栏浮层修复触摸问题; 常用功能/健康仪表盘间距收紧; _Panel 去外框
- 智能体: 欢迎卡片去掉 400ms 延迟; 胶囊去阴影
- 其他: api_client IP 适配; 多页面 UI 微调; 新增 chat_provider/prelaunch_guardrails 测试

health_app/lib/widgets/enterprise_widgets.dart

@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
+
 import '../core/app_colors.dart';
 import '../core/app_design_tokens.dart';
-import '../core/app_theme.dart';
 
 class EnterpriseStat {
   final String label;
@@ -177,97 +177,3 @@ class _HeaderStat extends StatelessWidget {
     );
   }
 }
-
-class EnterpriseSectionCard extends StatelessWidget {
-  final String? title;
-  final IconData? icon;
-  final Color color;
-  final Widget child;
-  final EdgeInsetsGeometry padding;
-  final Widget? trailing;
-
-  const EnterpriseSectionCard({
-    super.key,
-    this.title,
-    this.icon,
-    required this.color,
-    required this.child,
-    this.trailing,
-    this.padding = const EdgeInsets.all(16),
-  });
-
-  @override
-  Widget build(BuildContext context) {
-    return Container(
-      padding: padding,
-      decoration: BoxDecoration(
-        color: Colors.white,
-        borderRadius: BorderRadius.circular(16),
-        border: Border.all(color: AppColors.border, width: 1.1),
-        boxShadow: [AppTheme.shadowLight],
-      ),
-      child: Column(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          if (title != null) ...[
-            Row(
-              children: [
-                if (icon != null) ...[
-                  Container(
-                    width: 34,
-                    height: 34,
-                    decoration: BoxDecoration(
-                      color: color.withValues(alpha: 0.10),
-                      borderRadius: BorderRadius.circular(10),
-                    ),
-                    child: Icon(icon, size: 19, color: color),
-                  ),
-                  const SizedBox(width: 10),
-                ],
-                Expanded(
-                  child: Text(
-                    title!,
-                    maxLines: 1,
-                    overflow: TextOverflow.ellipsis,
-                    style: const TextStyle(
-                      fontSize: 17,
-                      fontWeight: FontWeight.w800,
-                      color: AppColors.textPrimary,
-                    ),
-                  ),
-                ),
-                ?trailing,
-              ],
-            ),
-            const SizedBox(height: 14),
-          ],
-          child,
-        ],
-      ),
-    );
-  }
-}
-
-class EnterpriseFab extends StatelessWidget {
-  final VoidCallback onPressed;
-  final IconData icon;
-  final Color color;
-
-  const EnterpriseFab({
-    super.key,
-    required this.onPressed,
-    required this.icon,
-    required this.color,
-  });
-
-  @override
-  Widget build(BuildContext context) {
-    return FloatingActionButton(
-      onPressed: onPressed,
-      backgroundColor: color,
-      elevation: 0,
-      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
-      child: Icon(icon, size: 26, color: Colors.white),
-    );
-  }
-}