fix: make SUPER_ADMIN role checks case-insensitive across app

Co-authored-by: aider (openai/DeepSeek-V3.2-Thinking) <aider@aider.chat>

inventory-backend/app/utils/decorators.py

@@ -63,8 +63,8 @@ def permission_required(permission_code):
 
             claims = get_jwt()
             user_role = claims.get('role')
-            # 超级管理员放行
-            if user_role == 'super_admin':
+            # 超级管理员放行 (忽略大小写)
+            if user_role and user_role.upper() == 'SUPER_ADMIN':
                 return fn(*args, **kwargs)
 
             # 根据角色查询数据库中的权限