[Feature]: 怎么添加agent？

### Summary

没有办法在命令行运行openclaw agents add xxx

### Problem to solve

需要在命令行运行openclaw agents add xxx

### Proposed solution

在命令行运行openclaw agents add xxx

### Alternatives considered

_No response_

### Impact

none

### Evidence/examples

_No response_

### Additional information

_No response_