- generate() now passes kwargs.get("model") into _resolve_model(), so the
user's hermes tools pick (forwarded by the dispatcher as top-level
image_gen.model) is honored instead of silently dropped (#55893 class;
matches xai/krea/openrouter).
- Setup schema badge "internal" -> "paid" to match every other paid
image backend in the hermes tools picker.
- Tests: caller-model precedence, unknown caller model falls through,
model kwarg reaches the API payload, badge contract.