refactor(ImageGallery, HomeScreen, PostService, UserStore): streamline post type handling and improve tab navigation

- Updated ImageGallery to manage loading states more effectively and prevent unnecessary updates.
- Refactored HomeScreen to remove the 'recommend' post type, simplifying the post type options.
- Adjusted PostService and UserStore to eliminate references to 'recommend', ensuring consistency across the application.
- Enhanced tab navigation in SimpleMobileTabNavigator to optimize rendering and manage mounted tabs more efficiently.
- Improved error handling and loading states in various components for better user experience.

src/components/common/ImageGallery.tsx

@@ -86,7 +86,9 @@ export const ImageGallery: React.FC<ImageGalleryProps> = ({
 }) => {
   const closeTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
   const isClosingRef = useRef(false);
+  const currentIndexRef = useRef(initialIndex);
   const [currentIndex, setCurrentIndex] = useState(initialIndex);
+  currentIndexRef.current = currentIndex;
   const [showControls, setShowControls] = useState(true);
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState(false);
@@ -152,16 +154,19 @@ export const ImageGallery: React.FC<ImageGalleryProps> = ({
     };
   }, []);
 
-  // 图片变化时重置加载状态和缩放
+  // 图片变化时重置缩放（加载态在 updateIndex / 打开弹窗时同步设置，避免晚一帧仍显示上一张）
   useEffect(() => {
-    setLoading(true);
-    setError(false);
     resetZoom();
   }, [currentImage?.id, resetZoom]);
 
   const updateIndex = useCallback(
     (newIndex: number) => {
       const clampedIndex = Math.max(0, Math.min(validImages.length - 1, newIndex));
+      if (clampedIndex === currentIndexRef.current) {
+        return;
+      }
+      setLoading(true);
+      setError(false);
       setCurrentIndex(clampedIndex);
       onIndexChange?.(clampedIndex);
     },
@@ -412,7 +417,8 @@ export const ImageGallery: React.FC<ImageGalleryProps> = ({
                     contentFit="contain"
                     cachePolicy="disk"
                     priority="high"
-                    recyclingKey={currentImage.id}
+                    recyclingKey={currentImage.url}
+                    transition={null}
                     allowDownscaling
                     onLoadStart={() => setLoading(true)}
                     onLoad={() => {
@@ -556,11 +562,13 @@ const styles = StyleSheet.create({
     justifyContent: 'center',
     alignItems: 'center',
     zIndex: 5,
+    backgroundColor: '#000',
   },
   errorContainer: {
     ...StyleSheet.absoluteFillObject,
     justifyContent: 'center',
     alignItems: 'center',
+    backgroundColor: '#000',
   },
   errorText: {
     color: '#999',