## Why
`additional_tools` response items were excluded from rollout persistence, dropping their tool definitions from saved history.
## What changed
- Persist `additional_tools` items in both legacy and paginated history modes.
- Expose the variant in generated JSON schemas, TypeScript types, and Python models, with an optional `id`, a `role`, and arbitrary JSON tool definitions.
## Testing
Add a recorder round-trip test that verifies tool definitions survive recording and loading in both history modes without parse errors.
GitOrigin-RevId: 0e7c7b1c10401ec6513fb744de642a1cf9e461d7
pakrym-oai
602d2add6e