refactor(auth): centralize auth routing via proxy and marker cookie

src/app/auth/components/auth-screen.tsx

@@ -13,10 +13,9 @@
 import { useEffect, useRef } from "react";
 import { useRouter } from "next/navigation";
 
-import { useAuthState, useAuthDispatch } from "@/stores/auth/auth-context";
+import { useAuthState } from "@/stores/auth/auth-context";
 import { useChatDispatch } from "@/stores/chat/chat-context";
 import { useUserDispatch } from "@/stores/user/user-context";
-import { useAuthGate } from "@/lib/auth/nextauth";
 import { ROUTES } from "@/router/routes";
 import { MobileShell } from "@/app/_components/core/mobile-shell";
 import { AuthPanel } from "@/app/auth/components/auth-panel";
@@ -29,19 +28,17 @@ export interface AuthScreenProps {
 export function AuthScreen({
   background = "var(--color-sidebar-background)",
 }: AuthScreenProps) {
+  // ===== 鉴权路由跳转已由 src/router/proxy.ts 集中处理 =====
+  // 本组件只负责：
+  //   1. 渲染登录面板
+  //   2. 登录成功后初始化 chat/user store + navigate 到 /chat（业务层动作）
+
   const router = useRouter();
-  const { isAuthed } = useAuthGate();
   const state = useAuthState();
-  const authDispatch = useAuthDispatch();
   const chatDispatch = useChatDispatch();
   const userDispatch = useUserDispatch();
   const wasSuccess = useRef(false);
 
-  // 已登录 → 自动跳 /chat
-  useEffect(() => {
-    if (isAuthed) router.replace(ROUTES.chat);
-  }, [isAuthed, router]);
-
   // 邮箱登录成功 → 通知 Chat + User + 跳转
   useEffect(() => {
     if (state.isSuccess && !wasSuccess.current) {