fix(api): truncate User-Agent to 255 chars in login audit log

WeChat in-app browser User-Agent exceeds 256 chars, causing MySQL

'Data too long for column browser' error on login

Truncate to [:255] before inserting into audit_login_log.browser"

Author: wjh-1024

cmdb-api/api/lib/perm/acl/audit.py

@@ -389,7 +389,7 @@ def add_login_log(cls, username, is_ok, description, _id=None, logout_at=None, i
                        logout_at=logout_at,
                        ip=(ip or request.headers.get('X-Forwarded-For') or
                            request.headers.get('X-Real-IP') or request.remote_addr or '').split(',')[0],
-                       browser=browser or request.headers.get('User-Agent'),
+                       browser=(browser or request.headers.get('User-Agent') or '')[:255],
                        channel=request.values.get('channel', 'web'),
                        )