[Feature]: 频道发送消息可以自定义

## Summary
在频道中使用agent的时候，如果不启用工具输出，就看不到agent的操作，如果启用，当工具调用输出过长会导致整个频道信息冗余

[One or two sentences: what do you want and why?]

希望可以截取部分输出，或者可以只显示工具调用信息和调用是否成功

这样可以用户自行选择是否查看完整输出

同时ai的思考过程也可以保留部分，而不是全部
## Component(s) Affected

- [ ] Core / Backend (app, agents, config, providers, utils, local_models)
- [ ] Console (frontend web UI)
- [ ] Channels (DingTalk, Feishu, QQ, Discord, iMessage, etc.)
- [ ] Skills
- [ ] CLI
- [ ] Documentation (website)
- [ ] Tests
- [ ] CI/CD
- [ ] Scripts / Deploy

## Problem / Motivation

[What problem does this solve? Who benefits?]

## Proposed Solution

[Describe the feature or change you have in mind. Be as specific as possible.]

## Alternatives Considered

[Any other approaches or workarounds you thought about.]

## Additional Context

[Screenshots, examples, links to docs or similar features elsewhere.]

## Willing to Contribute

- [ ] I am willing to open a PR for this feature (after discussion).