feat(identity): add gated self-hosted otp login

frontend/src/app/login/page.tsx

@@ -1,118 +1,7 @@
-"use client";
-
-import Image from "next/image";
-import { FormEvent, useState } from "react";
-import { createBrowserSupabaseClient } from "@/lib/supabase/client";
-
-function authMessage(caught: unknown) {
-  const message = caught instanceof Error ? caught.message : "暂时无法登录";
-  const lower = message.toLowerCase();
-  if (message.includes("Supabase") || message.includes("environment") || message.includes("URL")) return "Supabase 尚未配置";
-  if (lower.includes("expired") || lower.includes("invalid")) return "验证码错误或已过期，请重新获取";
-  if (lower.includes("rate limit")) return "发送过于频繁，请稍后再试";
-  return message;
-}
+import { EmailOtpLogin } from "@/components/email-otp-login";
+import { readIdentityConfig } from "@/modules/identity/config";
 
 export default function LoginPage() {
-  const [email, setEmail] = useState("");
-  const [token, setToken] = useState("");
-  const [sent, setSent] = useState(false);
-  const [busy, setBusy] = useState(false);
-  const [error, setError] = useState("");
-  const [notice, setNotice] = useState("");
-
-  async function sendOtp(event?: FormEvent<HTMLFormElement>) {
-    event?.preventDefault();
-    const normalizedEmail = email.trim();
-    if (!normalizedEmail || busy) return;
-    setBusy(true);
-    setError("");
-    setNotice("");
-    try {
-      const { error: otpError } = await createBrowserSupabaseClient().auth.signInWithOtp({
-        email: normalizedEmail,
-        options: { shouldCreateUser: true },
-      });
-      if (otpError) throw otpError;
-      setSent(true);
-      setNotice(`验证码已发送至 ${normalizedEmail}`);
-    } catch (caught) {
-      if (!(caught instanceof Error)) throw caught;
-      setError(authMessage(caught));
-    } finally {
-      setBusy(false);
-    }
-  }
-
-  async function verifyOtp(event: FormEvent<HTMLFormElement>) {
-    event.preventDefault();
-    if (!token || busy) return;
-    setBusy(true);
-    setError("");
-    try {
-      const { error: otpError } = await createBrowserSupabaseClient().auth.verifyOtp({
-        email: email.trim(),
-        token,
-        type: "email",
-      });
-      if (otpError) throw otpError;
-      window.location.assign("/");
-    } catch (caught) {
-      if (!(caught instanceof Error)) throw caught;
-      setError(authMessage(caught));
-      setBusy(false);
-    }
-  }
-
-  function changeEmail() {
-    setSent(false);
-    setToken("");
-    setError("");
-    setNotice("");
-  }
-
-  return (
-    <main className="standalone-page auth-page">
-      <div className="auth-shell">
-        <aside className="auth-story" aria-label="Jyotisha 简介">
-          <div className="auth-story-brand">
-            <Image src="/jyotish-logo.png" alt="" width={32} height={32} sizes="32px" />
-            <strong>Jyotisha</strong>
-          </div>
-          <div>
-            <p className="auth-kicker">Vedic astrology · 印度占星</p>
-            <h2>在星图与当下之间，<br />找到可以行动的<span className="phrase-nowrap">线索。</span></h2>
-            <p>以出生资料为起点，讨论事业、关系与时间窗口。每一次解读都保留证据，也保留你的选择。</p>
-          </div>
-          <p className="auth-footnote">私密对话 · 云端同步 · 随时继续</p>
-        </aside>
-
-        <section className="auth-panel" aria-labelledby="login-title">
-          <div className="auth-brand"><span aria-hidden="true" /><strong>Jyotisha</strong></div>
-          <h1 id="login-title">欢迎回来</h1>
-          <p className="page-intro">邮箱验证码登录，<span className="phrase-nowrap">新邮箱将自动创建账户。</span></p>
-
-          {!sent ? (
-            <form key="email" className="stack-form auth-step" onSubmit={sendOtp}>
-              <label htmlFor="login-email">邮箱</label>
-              <input id="login-email" type="email" autoComplete="email" inputMode="email" required autoFocus value={email} onChange={(event) => { setEmail(event.target.value); setError(""); setNotice(""); }} placeholder="you@example.com" />
-              <button className="button-primary" type="submit" disabled={!email.trim() || busy}>{busy ? "发送中" : "发送验证码"}</button>
-            </form>
-          ) : (
-            <form key="otp" className="stack-form auth-step" onSubmit={verifyOtp}>
-              <label htmlFor="login-token">邮箱验证码</label>
-              <input id="login-token" className="otp-input" type="text" autoComplete="one-time-code" inputMode="numeric" pattern="[0-9]*" minLength={6} maxLength={6} required autoFocus value={token} onChange={(event) => { setToken(event.target.value.replace(/\D/g, "").slice(0, 6)); setError(""); }} />
-              <button className="button-primary" type="submit" disabled={!token || busy}>{busy ? "验证中" : "验证并登录"}</button>
-              <div className="inline-actions">
-                <button type="button" disabled={busy} onClick={() => void sendOtp()}>{busy ? "发送中" : "重新发送验证码"}</button>
-                <button type="button" disabled={busy} onClick={changeEmail}>更换邮箱</button>
-              </div>
-            </form>
-          )}
-          {error && <p className="form-error" role="alert">{error}</p>}
-          {notice && <p className="form-success" role="status">{notice}</p>}
-        </section>
-      </div>
-    </main>
-  );
+  const config = readIdentityConfig(process.env);
+  return <EmailOtpLogin provider={config.provider} />;
 }