Add WeChat in-app JSAPI recharge for g2.tkmind.cn.

Use JSAPI with bound openid inside WeChat instead of QR long-press, and include related auth redirect and admin UX fixes.

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

wechat-pay.test.mjs

@@ -1,6 +1,7 @@
 import assert from 'node:assert/strict';
 import test from 'node:test';
 import {
+  buildV2JsapiParams,
   buildXml,
   createWechatPayClient,
   loadWechatPayConfig,
@@ -81,6 +82,18 @@ test('loadWechatPayConfig selects v2 when APIv2 key is configured', () => {
   }
 });
 
+test('buildV2JsapiParams signs prepay package for WeixinJSBridge', () => {
+  const config = {
+    appId: 'wxtestappid',
+    apiKey: 'test-api-v2-key-32chars-long!!!!',
+  };
+  const params = buildV2JsapiParams(config, 'wx201410272009395522657a690389285100');
+  assert.equal(params.appId, 'wxtestappid');
+  assert.equal(params.package, 'prepay_id=wx201410272009395522657a690389285100');
+  assert.equal(params.signType, 'MD5');
+  assert.match(params.paySign, /^[0-9A-F]{32}$/);
+});
+
 test('verifyNotify validates v2 callback signature', () => {
   const apiKey = 'test-api-v2-key-32chars-long!!!!';
   const fields = {