feat: 去除"问诊"字眼 + "药管家"改名 + 删除AI对话欢迎卡片紫色框

- "AI问诊" -> "AI对话"（胶囊名、首页标签、页面标题、提示词）
- "药管家" -> "药提醒"（胶囊名、枚举注释、处理器注释）
- AI对话欢迎卡片删除紫色提示框（与底部提示重复）
- 底部提示文字去掉"观察或就医建议"，改为"帮您记录和整理症状信息"

health_app/lib/pages/home/home_page.dart

@@ -386,7 +386,7 @@ class _HomePageState extends ConsumerState<HomePage>
     final module = switch (agent) {
       ActiveAgent.health => fromModule('记数据', AppModuleVisuals.health),
       ActiveAgent.diet => fromModule('拍饮食', AppModuleVisuals.diet),
-      ActiveAgent.medication => fromModule('药管家', AppModuleVisuals.medication),
+      ActiveAgent.medication => fromModule('药提醒', AppModuleVisuals.medication),
       ActiveAgent.report => fromModule('报告', AppModuleVisuals.report),
       ActiveAgent.exercise => fromModule('运动', AppModuleVisuals.exercise),
       _ => null,
@@ -402,13 +402,13 @@ class _HomePageState extends ConsumerState<HomePage>
 
     return switch (agent) {
       ActiveAgent.consultation => (
-        label: 'AI问诊',
+        label: 'AI对话',
         icon: LucideIcons.messageCircle,
         gradient: AppColors.doctorGradient,
         iconColor: Colors.white,
       ),
       _ => (
-        label: 'AI问诊',
+        label: 'AI对话',
         icon: LucideIcons.messageCircle,
         gradient: AppColors.primaryGradient,
         iconColor: Colors.white,