- POST /api/im/groups:创建群组(含成员列表) - GET /api/im/groups:按 appId 列出群组 - POST /api/im/groups/{groupId}/members:添加成员 - DELETE /api/im/groups/{groupId}/members/{targetUserId}:移除成员 ImGroupService 已有实现,仅补充 controller 层 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>