feat: 添加微信公众号网页授权域名验证文件路由

- 添加 /MP_verify_17Fo4JhapMw6vtNa.txt 路由
- 用于公众号后台网页授权域名验证

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app.py

@@ -1888,6 +1888,12 @@ def wechat_domain_verify():
     return 'd526e9e857dbd2621e5100811972e8c5', 200, {'Content-Type': 'text/plain'}
 
 
+@app.route('/MP_verify_17Fo4JhapMw6vtNa.txt', methods=['GET'])
+def wechat_mp_domain_verify():
+    """微信公众号网页授权域名校验文件"""
+    return '17Fo4JhapMw6vtNa', 200, {'Content-Type': 'text/plain'}
+
+
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