refactor(layout): share popup menu dismiss handling

The language and theme menus carried two identical outside-click/Escape effects; fold them into one useMenuDismiss hook.

src/components/layout/MainLayout.tsx

@@ -1,5 +1,6 @@
 import {
   ReactNode,
+  RefObject,
   SVGProps,
   useCallback,
   useEffect,
@@ -87,6 +88,39 @@ interface SidebarNavGroup {
 const flattenNavItems = (items: SidebarNavItem[]): SidebarNavLinkItem[] =>
   items.flatMap((item) => item.kind === 'drawer' ? item.children : [item]);
 
+/** 点击菜单外或按下 Escape 时关闭弹出菜单 */
+function useMenuDismiss(
+  open: boolean,
+  menuRef: RefObject<HTMLDivElement | null>,
+  onClose: () => void
+) {
+  useEffect(() => {
+    if (!open) {
+      return;
+    }
+
+    const handlePointerDown = (event: MouseEvent) => {
+      if (!menuRef.current?.contains(event.target as Node)) {
+        onClose();
+      }
+    };
+
+    const handleEscape = (event: KeyboardEvent) => {
+      if (event.key === 'Escape') {
+        onClose();
+      }
+    };
+
+    document.addEventListener('mousedown', handlePointerDown);
+    document.addEventListener('keydown', handleEscape);
+
+    return () => {
+      document.removeEventListener('mousedown', handlePointerDown);
+      document.removeEventListener('keydown', handleEscape);
+    };
+  }, [open, menuRef, onClose]);
+}
+
 function PluginSidebarIcon({ src }: { src: string }) {
   const [failed, setFailed] = useState(false);
   const showImage = Boolean(src) && !failed;
@@ -355,57 +389,10 @@ export function MainLayout() {
     };
   }, []);
 
-  useEffect(() => {
-    if (!languageMenuOpen) {
-      return;
-    }
-
-    const handlePointerDown = (event: MouseEvent) => {
-      if (!languageMenuRef.current?.contains(event.target as Node)) {
-        setLanguageMenuOpen(false);
-      }
-    };
-
-    const handleEscape = (event: KeyboardEvent) => {
-      if (event.key === 'Escape') {
-        setLanguageMenuOpen(false);
-      }
-    };
-
-    document.addEventListener('mousedown', handlePointerDown);
-    document.addEventListener('keydown', handleEscape);
-
-    return () => {
-      document.removeEventListener('mousedown', handlePointerDown);
-      document.removeEventListener('keydown', handleEscape);
-    };
-  }, [languageMenuOpen]);
-
-  useEffect(() => {
-    if (!themeMenuOpen) {
-      return;
-    }
-
-    const handlePointerDown = (event: MouseEvent) => {
-      if (!themeMenuRef.current?.contains(event.target as Node)) {
-        setThemeMenuOpen(false);
-      }
-    };
-
-    const handleEscape = (event: KeyboardEvent) => {
-      if (event.key === 'Escape') {
-        setThemeMenuOpen(false);
-      }
-    };
-
-    document.addEventListener('mousedown', handlePointerDown);
-    document.addEventListener('keydown', handleEscape);
-
-    return () => {
-      document.removeEventListener('mousedown', handlePointerDown);
-      document.removeEventListener('keydown', handleEscape);
-    };
-  }, [themeMenuOpen]);
+  const closeLanguageMenu = useCallback(() => setLanguageMenuOpen(false), []);
+  const closeThemeMenu = useCallback(() => setThemeMenuOpen(false), []);
+  useMenuDismiss(languageMenuOpen, languageMenuRef, closeLanguageMenu);
+  useMenuDismiss(themeMenuOpen, themeMenuRef, closeThemeMenu);
 
   const toggleLanguageMenu = useCallback(() => {
     setLanguageMenuOpen((prev) => !prev);