评论后端统一到 api.200181.xyz（与 RSS 同一 Worker）

评论与订阅已合并为同一个 Cloudflare Worker（artalk-cf，
同时服务 api.200181.xyz 与 artalk.200181.xyz）。为收敛到
单一域名/单一面板，评论入口统一切到 api.200181.xyz。

- hugo.toml params.artalk.server → api.200181.xyz
- write-server ARTALK_SERVER 默认值同步
- 注意：post.usj.cc 服务器 .env 里若有 ARTALK_SERVER 覆盖项需同步改

write-server/src/lib/config.ts

@@ -11,7 +11,7 @@ export const STATIC_DIR = path.join(BLOG_ROOT, "static");
 export const RECYCLE_DIR = path.join(process.cwd(), "recycle");
 export const RECYCLE_POSTS_DIR = path.join(RECYCLE_DIR, "posts");
 export const RECYCLE_META_DIR = path.join(RECYCLE_DIR, "meta");
-export const ARTALK_SERVER = process.env.ARTALK_SERVER || "https://artalk.200181.xyz";
+export const ARTALK_SERVER = process.env.ARTALK_SERVER || "https://api.200181.xyz";
 export const ARTALK_SITE = process.env.ARTALK_SITE || "优世界";
 export const ARTALK_ADMIN_EMAIL = process.env.ARTALK_ADMIN_EMAIL || "";
 export const ARTALK_ADMIN_PASSWORD = process.env.ARTALK_ADMIN_PASSWORD || "";