feat(wechat): send rich subscribe welcome with clickable intro and bind links

New followers receive capability overview plus WeChat anchor links for the
deep intro page and account binding instead of exposing raw URLs.

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

wechat-mp-config.mjs

@@ -4,6 +4,8 @@ const DEFAULT_STATUS_TEXT =
   '我在这边。上一条如果还没完成，我会继续把结果发给你；你也可以直接补一句要求。';
 const DEFAULT_UNSUPPORTED_TEXT = '当前先支持文字消息，你可以直接发文字给我。';
 const DEFAULT_UNBOUND_TEXT = '先点这里完成绑定，再继续和专属 Agent 对话：';
+const DEFAULT_SUBSCRIBE_INTRO_URL =
+  'https://m.tkmind.cn/MindSpace/a70ff537-8908-486e-9b6c-042e07cc25db/public/tkmind-deep-intro.html';
 const DEFAULT_PROGRESS_DELAY_MS = 8000;
 const DEFAULT_SESSION_IDLE_ROTATE_MS = 30 * 60 * 1000;
 const DEFAULT_SESSION_MESSAGE_ROTATE_COUNT = 200;
@@ -69,6 +71,8 @@ export function loadWechatMpConfig(env = process.env) {
     statusText: env.H5_WECHAT_MP_STATUS_TEXT?.trim() || DEFAULT_STATUS_TEXT,
     unsupportedText: env.H5_WECHAT_MP_UNSUPPORTED_TEXT?.trim() || DEFAULT_UNSUPPORTED_TEXT,
     unboundTextPrefix: env.H5_WECHAT_MP_UNBOUND_TEXT_PREFIX?.trim() || DEFAULT_UNBOUND_TEXT,
+    subscribeIntroUrl:
+      env.H5_WECHAT_MP_SUBSCRIBE_INTRO_URL?.trim() || DEFAULT_SUBSCRIBE_INTRO_URL,
     tokenUrl: env.H5_WECHAT_MP_TOKEN_URL?.trim() || DEFAULT_WECHAT_TOKEN_URL,
     customerServiceUrl:
       env.H5_WECHAT_MP_CUSTOMER_SERVICE_URL?.trim() || DEFAULT_WECHAT_CUSTOMER_SERVICE_URL,