refactor(core): optimize state management and component rendering performance

Improve application stability and performance by optimizing Zustand store usage, implementing memoization patterns, and introducing persistent authentication.

- **State Management**:
  - Refactor Zustand selectors to use `useShallow` and `getState()` to prevent unnecessary re-renders and infinite loops in hooks.
  - Implement `persist` middleware for `authStore` to maintain user sessions across restarts.
  - Introduce `buildStateCached` in `themeStore` to reduce redundant theme object computations.
- **Performance & Rendering**:
  - Implement `useMemo` for stable object/array references in `ImageGallery` and list components to prevent expensive re-renders.
  - Replace inline arrow functions with `useCallback` in complex screens like `ChatScreen` and `MessageListScreen`.
  - Optimize `FlashList` usage by providing stable `key` and `extraData` props.
- **Architecture**:
  - Decouple unread count fetching by introducing `useUnreadCountQuery` (React Query) for better caching and synchronization.
  - Add `useChannels` hook to centralize channel data fetching.
  - Refine `SessionGate` logic to allow immediate rendering of authenticated users while verifying in the background.

src/screens/profile/FollowListScreen.tsx

@@ -33,7 +33,7 @@ const FollowListScreen: React.FC = () => {
   const type = typeParam === 'followers' ? 'followers' : 'following';
   
   const { currentUser } = useAuthStore();
-  const { followUser, unfollowUser } = useUserStore();
+  const { followUser, unfollowUser } = useUserStore.getState();
   
   // 响应式布局
   const { isWideScreen, isDesktop, width } = useResponsive();

src/screens/profile/useUserProfile.ts

@@ -72,7 +72,8 @@ export const useUserProfile = (options: UseUserProfileOptions): UseUserProfileRe
   const insets = useSafeAreaInsets();
   const router = useRouter();
   
-  const { followUser, unfollowUser, posts: storePosts } = useUserStore();
+  const storePosts = useUserStore((state) => state.posts);
+  const { followUser, unfollowUser } = useUserStore.getState();
   const currentUser = useCurrentUser();
   
   // 状态