Add login gate, calculation history, and AI markdown download.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/api/auth/login/route.ts

@@ -0,0 +1,41 @@
+import { NextResponse } from "next/server";
+import {
+  isAuthEnabled,
+  verifyCredentials,
+} from "@/lib/auth/config";
+import {
+  createSessionToken,
+  SESSION_COOKIE,
+  SESSION_MAX_AGE_SEC,
+} from "@/lib/auth/session";
+
+export async function POST(req: Request) {
+  if (!isAuthEnabled()) {
+    return NextResponse.json({ ok: true, authEnabled: false });
+  }
+
+  let body: { username?: string; password?: string };
+  try {
+    body = await req.json();
+  } catch {
+    return NextResponse.json({ error: "请求格式错误" }, { status: 400 });
+  }
+
+  const username = body.username?.trim() ?? "";
+  const password = body.password ?? "";
+
+  if (!verifyCredentials(username, password)) {
+    return NextResponse.json({ error: "用户名或密码错误" }, { status: 401 });
+  }
+
+  const token = await createSessionToken(username);
+  const res = NextResponse.json({ ok: true, username });
+  res.cookies.set(SESSION_COOKIE, token, {
+    httpOnly: true,
+    sameSite: "lax",
+    secure: process.env.NODE_ENV === "production",
+    path: "/",
+    maxAge: SESSION_MAX_AGE_SEC,
+  });
+  return res;
+}

app/api/auth/logout/route.ts

@@ -0,0 +1,14 @@
+import { NextResponse } from "next/server";
+import { SESSION_COOKIE } from "@/lib/auth/session";
+
+export async function POST() {
+  const res = NextResponse.json({ ok: true });
+  res.cookies.set(SESSION_COOKIE, "", {
+    httpOnly: true,
+    sameSite: "lax",
+    secure: process.env.NODE_ENV === "production",
+    path: "/",
+    maxAge: 0,
+  });
+  return res;
+}

app/api/auth/me/route.ts

@@ -0,0 +1,19 @@
+import { NextResponse } from "next/server";
+import { cookies } from "next/headers";
+import { isAuthEnabled } from "@/lib/auth/config";
+import { getSessionUsername, SESSION_COOKIE } from "@/lib/auth/session";
+
+export async function GET() {
+  if (!isAuthEnabled()) {
+    return NextResponse.json({ authEnabled: false, loggedIn: true });
+  }
+
+  const token = (await cookies()).get(SESSION_COOKIE)?.value;
+  const username = await getSessionUsername(token);
+
+  return NextResponse.json({
+    authEnabled: true,
+    loggedIn: !!username,
+    username: username ?? undefined,
+  });
+}