feat(frontend): M9 模态 UI（mode 系统+共享 store+WS 客户端 + chat(思维链/工具回显/情绪徽标)/code/Agent 监控/后台思考页 + Miuix 设计 token + PWA）；tsc+vite build 通过

frontend/web/src/lib/useAsyncData.ts

@@ -0,0 +1,46 @@
+import { useCallback, useEffect, useRef, useState } from "react";
+
+interface AsyncState<T> {
+  data: T | null;
+  loading: boolean;
+  error: string | null;
+  reload: () => void;
+}
+
+/** Runs an async factory on mount (and on reload), tracking loading/error so
+ *  every API-backed surface has a complete state. Best-effort, no `any`. */
+export function useAsyncData<T>(fn: () => Promise<T>, deps: readonly unknown[] = []): AsyncState<T> {
+  const [data, setData] = useState<T | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const fnRef = useRef(fn);
+  fnRef.current = fn;
+  const depsKey = deps.join("\u0000");
+
+  const run = useCallback(() => {
+    let cancelled = false;
+    setLoading(true);
+    setError(null);
+    fnRef
+      .current()
+      .then((res) => {
+        if (!cancelled) setData(res);
+      })
+      .catch((err: unknown) => {
+        if (!cancelled) setError(err instanceof Error ? err.message : "加载失败");
+      })
+      .finally(() => {
+        if (!cancelled) setLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [depsKey]);
+
+  useEffect(() => {
+    const cancel = run();
+    return cancel;
+  }, [run]);
+
+  return { data, loading, error, reload: run };
+}