refactor: 简化 GridItem 组件的 Block 渲染逻辑，移除多余的边框样式

app/(tabs)/sync.tsx

@@ -723,12 +723,7 @@ const GridItem = memo(
 
     const canShow = post.status === 'completed' || post.status === 'success'
     return (
-      <Block
-        className="relative border border-yellow-200"
-        key={post?.id}
-        style={{ marginBottom: ITEM_GAP }}
-        onClick={() => onSelect(post)}
-      >
+      <Block className="relative" key={post?.id} style={{ marginBottom: ITEM_GAP }} onClick={() => onSelect(post)}>
         <Block
           className={`relative overflow-hidden border-2 ${isSelected ? 'shadow-[0px_0px_0px_4px_#FFE500]' : 'shadow-hard-black'} ${isSelected ? 'border-accent' : 'border-black'}`}
           style={{