source-part-segmentationlisted

# Source Part Segmentation Use this before `contour-to-mesh` when a source image contains overlapping or touching designed parts. The output is not “nice masks”; it is a **source-of-truth part inventory** that downstream geometry must obey. ## Inputs - source image, wireframe, decal, or texture atlas; - optional manual seed manifest with named parts, polygons, seed points, rough rectangles, or HSV/color ranges; - source manifest with structural/decorative/context classification and expected part count. ## Workflow 1. Choose the cleanest modality: alpha, edge, dark-line, bright-on-dark, color-band, or atlas region. 2. Extract contours and hierarchy to identify candidate objects, holes, nested details, and strokes. 3. If components touch, run distance-transform marker watershed first. 4. If watershed over/under-splits, switch to **seeded segmentation**: - create named part seeds (`bbox`, `polygon`, or `seed_point` + optional flood/HSV tolerance); - save one mask per named structural part; - mark ambiguous overlaps explicitly instead of merging them. 5. Classify masks as `structural`, `decorative`, `face_feature`, `aura_context`, or `validation_only`. 6. Pass structural masks to `contour-to-mesh`; pass feature masks/landmarks to `landmark-fit-repair`; pass atlas regions to `atlas-uv-fitting`. ## Hard rules - Do not infer repeated parts from symmetry; segment what the source shows. - Do not merge overlapping components if the manifest expects separate structural m