- Add GET /api/rotations endpoint to list all available rotations
- Add POST /api/rotations/chat/completions endpoint for rotation chat completions
- Model name in request now selects the specific rotation (coding, general, etc.)
- Add GET /api/rotations/models endpoint to list all models across all rotations
- Update root endpoint to show available rotations and autoselect options
- Maintain backward compatibility with existing /api/{provider_id} endpoints