- Add voyage-4-large/4/4-lite/4-nano + domain models to Voyage recipe
- Fix AI SDK compatibility: strip encoding_format (Voyage rejects 'float'),
patch response to add prompt_tokens from total_tokens
- Add embedding_provider doctor check: live smoke test verifying model,
API key, dimensions, and DB column alignment
- Add embedding provider eval qrels for post-migration quality testing
Closes: Voyage AI integration for gbrain embedding pipeline
