feat(settings): /settings 用户偏好编辑页

app/components/SignInButton.tsx

@@ -7,12 +7,13 @@ interface SignInButtonProps {
 }
 
 export function SignInButton({ className }: SignInButtonProps) {
-  // 直接跳转到后端 GitHub OAuth 授权入口（NEXT_PUBLIC_BACKEND_URL）
-  // 后端完成授权后带着 token 重定向回前端首页 /#token=xxx（fragment，不会出现在服务器日志中）
+  // 同源跳到 /oauth/render/github，经 next.config.mjs 的 rewrite 代理到后端。
+  // 好处：开发环境后端端口改来改去（8080 / 8081）都不用改前端；302 由 Next.js 透传给浏览器，
+  // 最终由浏览器跳到 GitHub 授权页。
+  // 注意：GitHub OAuth app 注册的 callback URL 决定最终返回的前端端口
+  // （当前注册为 localhost:3000/api/auth/callback/github），换端口跑本地时需在 GitHub OAuth app 里补一个。
   const handleSignIn = () => {
-    const backendUrl =
-      process.env.NEXT_PUBLIC_BACKEND_URL ?? "http://localhost:8080";
-    window.location.href = `${backendUrl}/oauth/render/github`;
+    window.location.href = "/oauth/render/github";
   };
 
   return (

app/components/UserMenu.tsx

@@ -1,5 +1,6 @@
 "use client";
 
+import Link from "next/link";
 import {
   Avatar,
   AvatarFallback,
@@ -36,32 +37,50 @@ export function UserMenu({ user, provider, logout }: UserMenuProps) {
         </Avatar>
       </summary>
 
-      <div className="absolute right-0 mt-2 w-60 overflow-hidden rounded-md border border-border bg-popover shadow-lg z-50">
-        <div className="border-b border-border bg-muted/40 px-4 py-3">
-          <p className="text-sm font-medium text-foreground">
+      {/*
+        下拉面板用显式的 bg-white / dark:bg-neutral-900 避免依赖 bg-popover
+        CSS 变量（原色值在某些主题下与 background 几乎同色导致看不清）。
+        每一项都显式 text-neutral-900 / dark:text-neutral-100 确保文字可读。
+      */}
+      <div className="absolute right-0 mt-2 w-60 overflow-hidden rounded-md border border-neutral-200 dark:border-neutral-700 bg-white dark:bg-neutral-900 shadow-xl z-50">
+        {/* 账号信息区 */}
+        <div className="border-b border-neutral-200 dark:border-neutral-700 bg-neutral-50 dark:bg-neutral-800 px-4 py-3">
+          <p className="text-sm font-medium text-neutral-900 dark:text-neutral-100">
             {user.name ?? "Signed in"}
           </p>
           {user.email ? (
-            <p className="text-xs text-muted-foreground" title={user.email}>
+            <p
+              className="text-xs text-neutral-500 dark:text-neutral-400"
+              title={user.email}
+            >
               {user.email}
             </p>
           ) : null}
         </div>
 
+        {/* 设置入口：登录用户均可见，指向 /settings 偏好页 */}
+        <Link
+          href="/settings"
+          className="block px-4 py-2 text-sm text-neutral-900 dark:text-neutral-100 transition hover:bg-neutral-100 dark:hover:bg-neutral-800"
+          data-umami-event="user_menu_settings_click"
+        >
+          设置
+        </Link>
+
         {provider === "github" ? (
           <a
             href="https://github.com/logout"
             target="_blank"
             rel="noreferrer"
-            className="block px-4 py-2 text-sm text-foreground transition hover:bg-muted"
+            className="block px-4 py-2 text-sm text-neutral-900 dark:text-neutral-100 transition hover:bg-neutral-100 dark:hover:bg-neutral-800"
           >
             切换 GitHub 账号（将在新标签页登出 GitHub）
           </a>
         ) : null}
 
         <button
           onClick={() => void logout()}
-          className="w-full px-4 py-2 text-left text-sm text-foreground transition hover:bg-muted"
+          className="w-full px-4 py-2 text-left text-sm text-neutral-900 dark:text-neutral-100 transition hover:bg-neutral-100 dark:hover:bg-neutral-800 border-t border-neutral-200 dark:border-neutral-700"
         >
           Sign out
         </button>

app/settings/SettingsForm.tsx

@@ -0,0 +1,284 @@
+"use client";
+
+// 用户偏好设置表单（Client Component）
+// 负责：拉取偏好数据、渲染编辑 UI、提交保存、同步 ThemeProvider
+
+import { useEffect, useRef, useState } from "react";
+import { useRouter } from "next/navigation";
+import { useAuth } from "@/lib/use-auth";
+import { useTheme } from "@/app/components/ThemeProvider";
+
+// 与后端 preferences 字段一一对应
+interface UserPreferences {
+  theme: "light" | "dark" | "system";
+  language: "zh" | "en";
+  aiDefaultProvider: "intern" | "openai" | "gemini";
+}
+
+const DEFAULT_PREFS: UserPreferences = {
+  theme: "system",
+  language: "zh",
+  aiDefaultProvider: "intern",
+};
+
+// 从 localStorage 读取 satoken
+function getToken(): string | null {
+  if (typeof window === "undefined") return null;
+  return localStorage.getItem("satoken");
+}
+
+// 骨架屏占位
+function SkeletonRow() {
+  return (
+    <div className="animate-pulse flex flex-col gap-2">
+      <div className="h-4 bg-neutral-200 dark:bg-neutral-700 rounded w-24" />
+      <div className="h-10 bg-neutral-100 dark:bg-neutral-800 rounded w-full" />
+    </div>
+  );
+}
+
+export function SettingsForm() {
+  const { status } = useAuth();
+  const { setTheme } = useTheme();
+  const router = useRouter();
+
+  const [prefs, setPrefs] = useState<UserPreferences>(DEFAULT_PREFS);
+  const [loading, setLoading] = useState(true);
+  const [saving, setSaving] = useState(false);
+  const [toast, setToast] = useState<{
+    type: "success" | "error";
+    msg: string;
+  } | null>(null);
+  // toast 定时器 ref：新 toast / 卸载时清掉旧 timer，避免 setState on unmounted
+  const toastTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  // 未登录时重定向
+  useEffect(() => {
+    if (status === "unauthenticated") {
+      router.replace("/login?redirect=/settings");
+    }
+  }, [status, router]);
+
+  // 拉取偏好数据
+  useEffect(() => {
+    if (status !== "authenticated") return;
+    const token = getToken();
+    // token 缺失时立刻结束 loading 并提示 + 跳转，否则页面会卡在骨架屏
+    if (!token) {
+      setLoading(false);
+      showToast("error", "登录态丢失，请重新登录");
+      router.replace("/login?redirect=/settings");
+      return;
+    }
+
+    fetch("/api/user-center/preferences", {
+      headers: { satoken: token },
+    })
+      .then((res) => {
+        if (!res.ok) throw new Error("获取偏好失败");
+        return res.json();
+      })
+      .then((body) => {
+        if (body?.success && body?.data) {
+          const merged = { ...DEFAULT_PREFS, ...body.data };
+          setPrefs(merged);
+          // 加载出来的 theme 立即同步到 ThemeProvider，避免"已保存设置与当前主题不一致"
+          setTheme(merged.theme);
+        }
+      })
+      .catch(() => {
+        showToast("error", "无法加载偏好设置，已显示默认值");
+      })
+      .finally(() => setLoading(false));
+    // setTheme 是 ThemeProvider 提供的稳定引用，router 同理；这里依赖 status 变化触发
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [status]);
+
+  // 组件卸载时清掉残留 toast timer
+  useEffect(() => {
+    return () => {
+      if (toastTimerRef.current) {
+        clearTimeout(toastTimerRef.current);
+      }
+    };
+  }, []);
+
+  function showToast(type: "success" | "error", msg: string) {
+    if (toastTimerRef.current) {
+      clearTimeout(toastTimerRef.current);
+    }
+    setToast({ type, msg });
+    toastTimerRef.current = setTimeout(() => setToast(null), 3000);
+  }
+
+  async function handleSave() {
+    const token = getToken();
+    // token 缺失时给明确反馈并跳转登录，而不是静默返回让用户摸不着头脑
+    if (!token) {
+      showToast("error", "登录态丢失，请重新登录后再保存");
+      router.replace("/login?redirect=/settings");
+      return;
+    }
+    setSaving(true);
+    try {
+      const res = await fetch("/api/user-center/preferences", {
+        method: "PATCH",
+        headers: {
+          "Content-Type": "application/json",
+          satoken: token,
+        },
+        body: JSON.stringify(prefs),
+      });
+      if (!res.ok) throw new Error("保存失败");
+      const body = await res.json();
+      if (body?.data) {
+        const merged: UserPreferences = { ...DEFAULT_PREFS, ...body.data };
+        setPrefs(merged);
+        // 主题变化立即同步到 ThemeProvider（同步写 localStorage）
+        setTheme(merged.theme);
+      }
+      showToast("success", "偏好设置已保存");
+    } catch {
+      showToast("error", "保存失败，请稍后重试");
+    } finally {
+      setSaving(false);
+    }
+  }
+
+  // 加载中或未登录均显示骨架屏，避免闪烁
+  if (status === "loading" || loading) {
+    return (
+      <div className="flex flex-col gap-8">
+        <SkeletonRow />
+        <SkeletonRow />
+        <SkeletonRow />
+      </div>
+    );
+  }
+
+  // 未认证时页面已重定向，此处不需要渲染
+  if (status === "unauthenticated") return null;
+
+  const themeOptions: { value: UserPreferences["theme"]; label: string }[] = [
+    { value: "light", label: "浅色" },
+    { value: "dark", label: "深色" },
+    { value: "system", label: "跟随系统" },
+  ];
+
+  const langOptions: { value: UserPreferences["language"]; label: string }[] = [
+    { value: "zh", label: "中文" },
+    { value: "en", label: "English" },
+  ];
+
+  const aiOptions: {
+    value: UserPreferences["aiDefaultProvider"];
+    label: string;
+  }[] = [
+    { value: "intern", label: "书生（InternLM）" },
+    { value: "openai", label: "OpenAI" },
+    { value: "gemini", label: "Gemini" },
+  ];
+
+  return (
+    <div className="flex flex-col gap-10">
+      {/* Toast 提示 */}
+      {toast && (
+        <div
+          className={`border px-4 py-3 font-mono text-sm ${
+            toast.type === "success"
+              ? "border-[var(--foreground)] bg-[var(--foreground)] text-[var(--background)]"
+              : "border-red-500 text-red-600 dark:text-red-400"
+          }`}
+        >
+          {toast.msg}
+        </div>
+      )}
+
+      {/* 主题设置 */}
+      <section>
+        <label className="block font-serif font-bold text-lg mb-3 uppercase tracking-wide">
+          主题
+        </label>
+        <div className="flex gap-0 border border-[var(--foreground)]">
+          {themeOptions.map(({ value, label }) => (
+            <button
+              key={value}
+              type="button"
+              onClick={() => setPrefs((p) => ({ ...p, theme: value }))}
+              className={`flex-1 py-2 px-4 font-mono text-sm uppercase transition-colors ${
+                prefs.theme === value
+                  ? "bg-[var(--foreground)] text-[var(--background)]"
+                  : "bg-transparent text-[var(--foreground)] hover:bg-neutral-100 dark:hover:bg-neutral-800"
+              }`}
+            >
+              {label}
+            </button>
+          ))}
+        </div>
+      </section>
+
+      {/* 语言设置 */}
+      <section>
+        <label className="block font-serif font-bold text-lg mb-3 uppercase tracking-wide">
+          语言
+        </label>
+        <div className="flex gap-0 border border-[var(--foreground)]">
+          {langOptions.map(({ value, label }) => (
+            <button
+              key={value}
+              type="button"
+              onClick={() => setPrefs((p) => ({ ...p, language: value }))}
+              className={`flex-1 py-2 px-4 font-mono text-sm uppercase transition-colors ${
+                prefs.language === value
+                  ? "bg-[var(--foreground)] text-[var(--background)]"
+                  : "bg-transparent text-[var(--foreground)] hover:bg-neutral-100 dark:hover:bg-neutral-800"
+              }`}
+            >
+              {label}
+            </button>
+          ))}
+        </div>
+      </section>
+
+      {/* AI 默认提供商 */}
+      <section>
+        <label
+          htmlFor="ai-provider"
+          className="block font-serif font-bold text-lg mb-3 uppercase tracking-wide"
+        >
+          AI 默认提供商
+        </label>
+        <select
+          id="ai-provider"
+          value={prefs.aiDefaultProvider}
+          onChange={(e) =>
+            setPrefs((p) => ({
+              ...p,
+              aiDefaultProvider: e.target
+                .value as UserPreferences["aiDefaultProvider"],
+            }))
+          }
+          className="w-full border border-[var(--foreground)] bg-[var(--background)] text-[var(--foreground)] font-mono text-sm px-4 py-2 appearance-none focus:outline-none focus:ring-2 focus:ring-[var(--foreground)]"
+        >
+          {aiOptions.map(({ value, label }) => (
+            <option key={value} value={value}>
+              {label}
+            </option>
+          ))}
+        </select>
+      </section>
+
+      {/* 提交按钮 */}
+      <div className="border-t border-neutral-200 dark:border-neutral-700 pt-6">
+        <button
+          type="button"
+          onClick={handleSave}
+          disabled={saving}
+          className="font-mono text-sm uppercase tracking-widest px-8 py-3 border-2 border-[var(--foreground)] bg-[var(--foreground)] text-[var(--background)] hover:bg-transparent hover:text-[var(--foreground)] transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
+        >
+          {saving ? "保存中..." : "保存设置"}
+        </button>
+      </div>
+    </div>
+  );
+}

app/settings/page.tsx

@@ -0,0 +1,28 @@
+// 用户偏好设置页（Server Component）
+// 登录态由客户端 SettingsForm 内部的 useAuth 处理：token 存在 localStorage，服务端无法读取，
+// 所以这里不做服务端鉴权，仅负责渲染页面壳。未登录 → 客户端 router.replace 到 /login?redirect=/settings。
+import { Header } from "@/app/components/Header";
+import { Footer } from "@/app/components/Footer";
+import { SettingsForm } from "./SettingsForm";
+
+export default function SettingsPage() {
+  return (
+    <>
+      <Header />
+      <main className="min-h-screen pt-32 pb-16 newsprint-texture">
+        <div className="container mx-auto px-6 max-w-2xl">
+          <div className="mb-10 border-b-4 border-[var(--foreground)] pb-4">
+            <h1 className="text-5xl font-serif font-black uppercase text-[var(--foreground)]">
+              Settings
+            </h1>
+            <p className="font-mono text-sm uppercase tracking-widest mt-3 text-neutral-500">
+              User Preferences — Customize your experience
+            </p>
+          </div>
+          <SettingsForm />
+        </div>
+      </main>
+      <Footer />
+    </>
+  );
+}