feat(mp): U3-1 医生端导航状态保持

- 新增 useNavigationState hook (saveDoctorPage/getDoctorLastPage)
- 首页医生重定向使用 getDoctorLastPage 代替硬编码路径
- 医生端工作台入口自动保存最后访问路径
- 医生再次打开首页时自动回到上次使用的医生端页面

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

@@ -6,6 +6,7 @@ import { useAuthStore } from '../../stores/auth';
 import { useUIStore } from '../../stores/ui';
 import { navigateToLogin } from '../../utils/navigate';
 import { usePageData } from '@/hooks/usePageData';
+import { getDoctorLastPage } from '@/hooks/useNavigationState';
 // useThrottledDidShow removed — unused import
 import { api } from '@/services/request';
 import type { Article } from '@/services/article';
@@ -352,8 +353,9 @@ export default function Index() {
   useDidShow(() => {
     if (shouldRedirect && !redirectingRef.current) {
       redirectingRef.current = true;
+      const target = getDoctorLastPage();
       Taro.reLaunch({
-        url: '/pages/pkg-doctor-core/index',
+        url: target,
         fail: () => {
           redirectingRef.current = false;
           console.warn('跳转医生端失败，停留患者首页');

apps/miniprogram/src/pages/pkg-doctor-core/index.tsx

@@ -4,6 +4,7 @@ import { safeNavigateTo } from '@/utils/navigate';
 import { useAuthStore } from '@/stores/auth';
 import { useDoctorClass } from '@/hooks/useDoctorClass';
 import { usePageData } from '@/hooks/usePageData';
+import { saveDoctorPage } from '@/hooks/useNavigationState';
 import { getDashboard, type DoctorDashboard } from '@/services/doctor/dashboard';
 import Loading from '@/components/Loading';
 import ContentCard from '@/components/ui/ContentCard';
@@ -68,6 +69,7 @@ export default function DoctorHome() {
   }, []);
 
   usePageData(loadDashboard, { throttleMs: 10000 });
+  saveDoctorPage('/pages/pkg-doctor-core/index');
 
   const getValue = (key: keyof DoctorDashboard): number | string => {
     if (!dashboard) return '-';