## 1. Validation updates

- [x] 1.1 Remove local rejection for Responses input_file.file_id
- [x] 1.2 Reject chat input_audio as unsupported in validation
- [x] 1.3 Allow chat file_id mapping to pass through

## 2. Docs and live checks

- [x] 2.1 Update support matrix and live check expectations for audio/file_id behavior
- [x] 2.2 Update integration/unit tests for file_id pass-through and audio rejection
