feat(ai): Day 5 — ChatResponse display_hints + Web RichMessage 渲染

- ChatResponse 增加 display_hints 字段，Orchestrator 收集 Tool 产生的 DisplayHint
- DisplayHint 实现 utoipa::ToSchema
- Web ChatResponse 类型同步，DisplayHint 8 种联合类型
- RichMessage 组件：InsightCard/RiskAlert/LabReportCard/TrendChart/PatientProfile/VitalCard
- AiSidebar 消息中渲染 display_hints 富消息
- 小程序 AiChatResponse 类型同步

apps/web/src/api/ai/chat.ts

@@ -5,10 +5,53 @@ export interface ChatHistoryItem {
   content: string;
 }
 
+export type DisplayHint =
+  | {
+      type: 'vital_card';
+      indicator_type: string;
+      values: [string, number][];
+      unit: string;
+    }
+  | {
+      type: 'lab_report_card';
+      report_date: string;
+      abnormal_count: number;
+    }
+  | {
+      type: 'action_confirm';
+      action_type: string;
+      summary: string;
+      confirm_payload: unknown;
+    }
+  | {
+      type: 'risk_alert';
+      level: string;
+      message: string;
+    }
+  | {
+      type: 'trend_chart';
+      metrics: string[];
+      period: string;
+      summary: string;
+    }
+  | {
+      type: 'insight_card';
+      title: string;
+      severity: string;
+      items: string[];
+    }
+  | {
+      type: 'patient_profile';
+      chronic_conditions: string[];
+      medication_count: number;
+    }
+  | { type: 'text' };
+
 export interface ChatResponse {
   reply: string;
   message_id: string;
   iterations: number;
+  display_hints?: DisplayHint[];
 }
 
 export const aiChatApi = {