Preserve distal anatomy and pin vascular quality regressions

[PaleRoses]

Scope

• establish GitHub as the durable workspace for the reconstructed live kernel
• measure distal endpoint retention, section radii, taper, contact patches, shell continuity, and silhouette landmarks
• preserve feet, lower legs, and tail tips through feature-aware adaptive refinement and formed-skin feature protection
• add canonical distal authoring semantics and distinct pawed/hoofed or web-footed witnesses
• pin vascular status, topology, clearance, residual, and terminal coverage as independent no-regression gates

Required gates

• semantic kernel
• final systems
• distal quality corpus
• vascular regression corpus
• clean release packaging

Generated meshes and view sheets are CI/release artifacts; source, specs, metric definitions, tests, and JSON receipts remain repository-owned.