完善文档与前端迁移，补充开源协议

web/src/app/api/auth/logout/route.ts

@@ -0,0 +1,17 @@
+import { cookies } from "next/headers";
+import { NextResponse } from "next/server";
+
+import { SESSION_COOKIE_NAME } from "@/lib/api/config";
+
+async function clearSession() {
+  cookies().delete(SESSION_COOKIE_NAME);
+  return NextResponse.json({ ok: true });
+}
+
+export async function POST() {
+  return clearSession();
+}
+
+export async function GET() {
+  return clearSession();
+}