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/message/GroupMembersScreen.tsx

@@ -27,11 +27,11 @@ import { spacing, fontSizes, borderRadius, useAppColors, type AppColors } from '
 import { useAuthStore } from '../../stores';
 import { groupService } from '@/services/message';
 import {
-  createRemoteGroupMemberListSource,
+  createCursorGroupMemberListSource,
   GroupMemberListSourceKind,
-  IGroupMemberListPagedSource,
-} from '../../stores/groupMemberListSources';
-import { enrichGroupMembersWithUserProfiles } from '../../stores/groupMemberProfileResolver';
+  ICursorGroupMemberListPagedSource,
+} from '../../stores/group';
+import { enrichGroupMembersWithUserProfiles } from '../../stores/group';
 import { Avatar, Text, Button, Loading, EmptyState, Divider, ResponsiveContainer, AppBackButton } from '../../components/common';
 import { useResponsive, useBreakpointGTE } from '../../hooks/useResponsive';
 import { useCursorPagination } from '../../hooks/useCursorPagination';
@@ -75,8 +75,8 @@ const GroupMembersScreen: React.FC = () => {
     return GRID_CONFIG.mobile;
   }, [width]);
 
-  const memberListSource = useMemo<IGroupMemberListPagedSource>(() => {
-    return createRemoteGroupMemberListSource(GROUP_MEMBER_REMOTE_LIST_KIND, groupId, 50);
+  const memberListSource = useMemo<ICursorGroupMemberListPagedSource>(() => {
+    return createCursorGroupMemberListSource(GROUP_MEMBER_REMOTE_LIST_KIND, groupId, 50);
   }, [groupId]);
 
   // 使用统一数据源 + 游标 Hook 管理成员列表