fix: 后台侧边栏单成员组渲染崩溃（React #31——对象数组直接当子元素，改为统一 map 渲染并保留多组折叠）

frontend/src/admin/AdminLayout.jsx

@@ -121,23 +121,26 @@ export default function AdminLayout() {
   const renderGroup = (g) => {
     const single = g.items.length === 1;
     const open = openGroups.has(g.id);
-    const items = (single ? g.items : (
+    const itemList = (
+      <List component="div" disablePadding>
+        {g.items.map((item) => (
+          <ListItemButton
+            key={item.path}
+            selected={location.pathname.startsWith(item.path)}
+            onClick={() => { goMenu(item.path); }}
+            sx={{ pl: single ? 2 : 4 }}
+          >
+            <ListItemIcon>{item.icon ? <item.icon fontSize="small" /> : null}</ListItemIcon>
+            <ListItemText primary={item.label} primaryTypographyProps={{ fontSize: 14 }} />
+          </ListItemButton>
+        ))}
+      </List>
+    );
+    const items = single ? itemList : (
       <Collapse in={open} timeout="auto" unmountOnExit>
-        <List component="div" disablePadding>
-          {g.items.map((item) => (
-            <ListItemButton
-              key={item.path}
-              selected={location.pathname.startsWith(item.path)}
-              onClick={() => { goMenu(item.path); }}
-              sx={{ pl: 4 }}
-            >
-              <ListItemIcon>{item.icon ? <item.icon fontSize="small" /> : null}</ListItemIcon>
-              <ListItemText primary={item.label} primaryTypographyProps={{ fontSize: 14 }} />
-            </ListItemButton>
-          ))}
-        </List>
+        {itemList}
       </Collapse>
-    ));
+    );
 
     return (
       <Box key={g.id}>