refactor(admin): LiteMermaid 用 usehooks-ts useIsMounted 替代手写 cancelled 标志

apps/admin/src/components/AiChat/LiteMermaid.tsx

@@ -1,4 +1,5 @@
 import { useEffect, useRef, useState } from 'react';
+import { useIsMounted } from 'usehooks-ts';
 
 interface LiteMermaidProps {
   children: string;
@@ -11,9 +12,9 @@ interface LiteMermaidProps {
 export function LiteMermaid({ children }: LiteMermaidProps) {
   const containerRef = useRef<HTMLDivElement>(null);
   const [error, setError] = useState<string | null>(null);
+  const isMounted = useIsMounted();
 
   useEffect(() => {
-    let cancelled = false;
     const container = containerRef.current;
     if (!container) return;
 
@@ -22,21 +23,17 @@ export function LiteMermaid({ children }: LiteMermaidProps) {
         const mermaid = (await import('mermaid')).default;
         mermaid.initialize({ startOnLoad: false, theme: 'neutral', securityLevel: 'strict' });
         const { svg } = await mermaid.render(`mermaid-${crypto.randomUUID()}`, children);
-        if (!cancelled) {
+        if (isMounted()) {
           const doc = new DOMParser().parseFromString(svg, 'image/svg+xml');
           container.replaceChildren(doc.documentElement);
           setError(null);
         }
       } catch (e) {
-        if (!cancelled) {
+        if (isMounted()) {
           setError(e instanceof Error ? e.message : '图表渲染失败');
         }
       }
     })();
-
-    return () => {
-      cancelled = true;
-    };
   }, [children]);
 
   if (error) {