[Feature]: 免认证主机白名单支持配置CIDR 段

## Summary

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

## Component(s) Affected

- [x] 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
免认证主机白名单目前不支持配置CIDR 段
[What problem does this solve? Who benefits?]
解决运维内网地址段，受益人员应为平台、系统运维人员
## 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).