## Summary

Brief description of the changes.

## Related Issue

Closes #<issue_number>

## Changes

- ...

## Test Plan

- [ ] I tested these changes locally
- [ ] Tests pass (`uv run pytest --cov=src/notebooklm --cov-report=term-missing --cov-report=json:coverage.json --cov-fail-under=90`)
- [ ] Linting and formatting pass (`uv run pre-commit run --all-files`)
- [ ] Type checking passes (`uv run mypy src/notebooklm --ignore-missing-imports`)
- [ ] If this PR changes architectural shape, an ADR has been added or updated.

## Notes

Any additional context, trade-offs, or design decisions.