Agent Skills: surface-forks

Use during any implementation, design, refactor, or debugging task, in any language or codebase. Before changing anything that touches an existing domain concept, rule, type, or invariant, find what the change collides with and name the routes through it — instead of letting the first workable route settle the question silently. Trigger on any request to build, change, model, extend, or restructure, including small changes and including when the user says nothing about design. Do NOT use for purely additive isolated code, pure explanation, or review with no change proposed.