OmoConfig interface was missing variant property, causing doctor to show
variants from ModelRequirement fallback chain instead of user's config.
- Add variant to OmoConfig agent/category entries
- Add userVariant to resolution info interfaces
- Update getEffectiveVariant to prioritize user variant
- Add tests verifying variant capture
- Changed fetchAvailableModels to read from ~/.cache/opencode/models.json
- Prevents plugin startup hanging caused by SDK client.config.providers() call
- Updated doctor model-resolution check to show available models from cache
- Added cache info display: provider count, model count, refresh command
Add new 'model-resolution' check to diagnose model fallback chain health. Validates that configured agents and categories can resolve to available models, surfacing misconfiguration early.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
