Replace singular reference_image field with reference_images list to
support an arbitrary number of reference images. Map them to the correct
BFL API parameter names based on model family:
- flux-2-*: input_image, input_image_2, ..., input_image_8
- flux-kontext-*: input_image, input_image_2, ..., input_image_4
- flux 1.x: image_prompt (single)
BREAKING CHANGE: reference_image config field renamed to reference_images (list).
- Replace pyright with basedpyright in devenv.nix (custom hook)
- Add basedpyright to devenv packages
- Fix all basedpyright warnings: add DiGraph[str] type args, annotate
class attributes, narrow SyncResponse, handle unused call results,
suppress unavoidable Any from yaml.safe_load and untyped blackforest
- Replace pydantic-settings[yaml] with direct pyyaml dependency
- Update CLAUDE.md to reflect basedpyright and dependency changes
- TargetType enum with IMAGE/TEXT variants
- Defaults, TargetConfig, ProjectConfig pydantic models
- infer_target_type() for extension-based type dispatch
- resolve_model() for default/override model resolution
- load_config() using yaml.safe_load + model_validate
