feat(miniprogram): 埋点事件追踪服务

- 新增 analytics.ts：trackEvent/trackPageView/flushEvents
- 事件队列本地缓存，批量上报到 /analytics/batch
- 首页 page_view、预约创建、随访提交、健康数据录入四个关键埋点

apps/miniprogram/src/pages/health/input/index.tsx

@@ -5,6 +5,7 @@ import { z } from 'zod';
 import { inputVitalSign } from '../../../services/health';
 import { useAuthStore } from '../../../stores/auth';
 import { useHealthStore } from '@/stores/health';
+import { trackEvent } from '@/services/analytics';
 import './index.scss';
 
 const INDICATORS = [
@@ -76,6 +77,7 @@ export default function HealthInput() {
       });
       clearCache();
       Taro.showToast({ title: '录入成功', icon: 'success' });
+      trackEvent('health_data_input', { type: indicatorType });
       setTimeout(() => Taro.navigateBack(), 1000);
     } catch (e: unknown) {
       const msg = e instanceof Error ? e.message : '录入失败';