Complete SHiRE Academy round 3 using only the supplied skill data. Follow the round-specific JSON schema exactly and stay concise. Do not answer sections assigned to another round. Do not claim tool execution or physical validation.
{"skill_id":"geometry_foundations.chamfers","name":"Chamfers","domain":"geometry_foundations","risk":"low","lane":"tool_evidence","professional_review":false,"round":3,"focus":"transfer to another harmless use with measurable acceptance","principles":["Use explicit units, origins, axes and coordinate systems.","Prefer constrained construction geometry for functional features.","Maintain closed, valid solids for manufacturing."],"failure_signals":["Non-manifold or self-intersecting output.","Inverted normals or disconnected shells."],"application":"harmless household design example","response_scope":"transfer boundaries release gate only"}