fix(auth): read redirect on client

src/app/auth/auth-screen.tsx

@@ -4,7 +4,7 @@
  *
  * 原始 Dart: lib/ui/auth/auth_screen.dart
  */
-import { useEffect } from "react";
+import { useEffect, useSyncExternalStore } from "react";
 import { useRouter } from "next/navigation";
 
 import { MobileShell } from "@/app/_components/core";
@@ -17,14 +17,15 @@ import { Logger } from "@/utils";
 
 const log = new Logger("AppAuthAuthScreen");
 
-export interface AuthScreenProps {
-  redirectTo?: string | null;
-}
-
-export function AuthScreen({ redirectTo = null }: AuthScreenProps) {
+export function AuthScreen() {
   const state = useAuthState();
   const authDispatch = useAuthDispatch();
   const router = useRouter();
+  const redirectTo = useSyncExternalStore(
+    subscribeLocationSnapshot,
+    readRedirectFromLocation,
+    () => null,
+  );
   const safeRedirectTo = getSafeRedirectPath(redirectTo) ?? ROUTES.chat;
 
   // 邮箱登录成功 → 跳转；User hydrate 由根级 <UserAuthSync /> 监听 loginStatus 变化处理。
@@ -70,3 +71,12 @@ function getSafeRedirectPath(redirectTo: string | null | undefined): string | nu
   if (!redirectTo.startsWith("/") || redirectTo.startsWith("//")) return null;
   return redirectTo;
 }
+
+function readRedirectFromLocation(): string | null {
+  if (typeof window === "undefined") return null;
+  return new URLSearchParams(window.location.search).get("redirect");
+}
+
+function subscribeLocationSnapshot(): () => void {
+  return () => {};
+}

src/app/auth/page.tsx

@@ -1,16 +1,5 @@
 import { AuthScreen } from "@/app/auth/auth-screen";
 
-interface AuthPageProps {
-  searchParams: Promise<{
-    redirect?: string | string[];
-  }>;
-}
-
-export default async function AuthPage({ searchParams }: AuthPageProps) {
-  const params = await searchParams;
-  const redirectTo = Array.isArray(params.redirect)
-    ? params.redirect[0]
-    : params.redirect;
-
-  return <AuthScreen redirectTo={redirectTo ?? null} />;
+export default function AuthPage() {
+  return <AuthScreen />;
 }