Add OpenCode to provider autocomplete enum (#55586)
Adrian Lumpe
created
The `opencode` built-in provider is registered in the language model
registry
but missing from the JSON schema enum in `LanguageModelProviderSetting`.
<img width="724" height="399" alt="image"
src="https://github.com/user-attachments/assets/33da4626-eb44-443e-b656-65533b3a85f1"
/>
<br>
OpenCode is one of the "first class" providers, so I was surprised it
was missing from the auto-complete for the provider fields in the
settings file.
## Self-Review Checklist
- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable
## Release Notes
- N/A