Code review polish:
- Add stderr warning for the fourth failure path (LLM returned valid
JSON but it's not a list-of-strings). Previously this fell back
silently, making debugging harder when Haiku produces unexpected
shapes.
- Drop unused f-string prefixes from two warnings (no interpolation).
- Type hint: Callable[..., str] = None → Optional[Callable[..., str]] = None
for strict type-checker compatibility.
12/12 tests still pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Andrew Yim
5f6438ecf3