refactor(stores): reorganize flat store files into modular directory structure

Migrate from flat file organization to modular directory structure under src/stores/:

- auth/: authStore, registerStore, verificationStore, sessionStore
- call/: callStore
- settings/: chatSettingsStore, themeStore
- ui/: homeTabBarVisibilityStore, homeTabPressStore
- utils/: routePayloadCache
- group/sources.ts, group/profileResolver.ts
- message/sources.ts
- post/sources.ts

Update all import paths across components and screens to use new module paths. Maintain backward compatibility through deprecated re-export files for gradual migration.

src/screens/home/HomeScreen.tsx

@@ -27,7 +27,7 @@ import { PagerView } from '../../components/common';
 import { useAppColors, useResolvedColorScheme, spacing, borderRadius, shadows, type AppColors } from '../../theme';
 import { Post } from '../../types';
 import { useUserStore, useHomeTabBarVisibilityStore, useHomeTabPressStore } from '../../stores';
-import { useCurrentUser } from '../../stores/authStore';
+import { useCurrentUser } from '../../stores/auth';
 import { channelService, postService } from '../../services';
 import { PostCard, TabBar, SearchBar } from '../../components/business';
 import type { PostCardAction } from '../../components/business/PostCard';
@@ -466,9 +466,9 @@ export const HomeScreen: React.FC = () => {
   
   // 宽屏下内容最大宽度
   const contentMaxWidth = useMemo(() => {
-    if (isWideScreen) return 800;
-    if (isDesktop) return 720;
-    if (isTablet) return 640;
+    if (isWideScreen) return 1200;
+    if (isDesktop) return 1000;
+    if (isTablet) return 800;
     return width; // 移动端使用全宽
   }, [width, isTablet, isDesktop, isWideScreen]);
 

src/screens/home/PostDetailScreen.tsx

@@ -35,7 +35,7 @@ import {
 } from '../../theme';
 import { Post, Comment, VoteResultDTO, VoteOptionDTO } from '../../types';
 import { useUserStore } from '../../stores';
-import { useCurrentUser } from '../../stores/authStore';
+import { useCurrentUser } from '../../stores/auth';
 import { postService, commentService, uploadService, authService, showPrompt, voteService } from '../../services';
 import { postSyncService } from '@/services/post';
 import { useCursorPagination } from '../../hooks/useCursorPagination';