fix(auth,audit): ensure display_name persists in token refresh and add fallback in audit log

inventory-backend/app/utils/decorators.py

@@ -205,6 +205,17 @@ def audit_log(module: str, action: str = None, get_target_id_fn=None, get_target
             username = claims.get('username', '')
             display_name = claims.get('display_name', '')
 
+            # 兜底：如果 display_name 为空，查询数据库获取
+            if not display_name and user_id:
+                try:
+                    from app.models.system import SysUser
+                    user = SysUser.query.get(user_id)
+                    if user:
+                        user_info = user.to_dict()
+                        display_name = user_info.get('display_name', username)
+                except Exception:
+                    pass
+
             # 获取IP
             ip_address = request.headers.get('X-Forwarded-For') or request.remote_addr or ''
             if ip_address and ',' in ip_address: