[Feature Request] Improve file completion suggestions for `@` prefix with smarter ranking

Question

**Bug Description**
file completion with `@` prefix: i found that opencode has a much better suggestion method for local files. using claude, i always have to look twice and sometimes wonder how particular files made it into the list of suggestions.

**Environment Info**
- Platform: darwin
- Terminal: ghostty
- Version: 2.1.150
- Feedback ID: 726b19cd-ecf4-4f74-991e-2ed006e14382

**Errors**
```json
[]
```