feat(profile): add data storage settings screen with cache management

Add DataStorageScreen for managing media cache and storage:
- Display cache statistics (image/video/audio counts and sizes)
- Show AsyncStorage usage information
- Add clear all cache functionality
- Add cleanup expired cache option (7 days threshold)
- Add storage usage breakdown by category
- Add "Last cleaned" timestamp display

Also fix MediaCacheManager to skip native cache operations on web platform:
- Return original URI directly on web without caching
- Skip directory creation on web
- Skip file existence checks on web
- Skip startup and periodic cleanup on web

app/(app)/(tabs)/profile/_layout.tsx

@@ -41,6 +41,7 @@ export default function ProfileStackLayout() {
       <Stack.Screen name="terms" options={{ title: '用户协议' }} />
       <Stack.Screen name="privacy" options={{ title: '隐私政策' }} />
       <Stack.Screen name="verification" options={{ title: '身份认证' }} />
+      <Stack.Screen name="data-storage" options={{ title: '数据与存储' }} />
     </Stack>
   );
 }