refactor(navigation): consolidate navigation with href helpers and extract push device hook

- Migrate all navigation calls from magic strings to centralized href helpers
- Extract inline device registration logic into useRegisterPushDevice hook
- Remove unused terms and privacy policy routes from profile stack
- Add hrefTradeDetail helper for trade detail navigation
- Restore routePayloadCache.stashSystemMessage for group request/invite handling
- Change desktop shell tab navigation from replace to push

src/screens/home/HomeScreen.tsx

@@ -716,7 +716,7 @@ export const HomeScreen: React.FC = () => {
   // 跳转到发帖页面（使用 Modal 方式）
   const handleCreatePost = () => {
     if (!isAuthenticated) {
-      router.push('/login');
+      router.push(hrefs.hrefAuthLogin());
       return;
     }
     if (!isVerified) {
@@ -1052,7 +1052,7 @@ export const HomeScreen: React.FC = () => {
           floatingButtonBottom !== undefined && { bottom: floatingButtonBottom },
         ]}
         onPress={homeTab === 'market' ? () => {
-          if (!isAuthenticated) { router.push('/login'); return; }
+          if (!isAuthenticated) { router.push(hrefs.hrefAuthLogin()); return; }
           if (!isVerified) { router.push(hrefs.hrefVerificationGuide()); return; }
           setShowCreateTrade(true);
         } : handleCreatePost}