测试驱动开发（活规格 TDD）

关于这个 Skill

Test-driven development (TDD) for NON-TRIVIAL behavior — write a failing test FIRST, watch it fail with evidence, then minimal code to pass; the suite is a LIVING SPEC you edit/merge/delete. Use when implementing real logic, fixing a bug with a regression test, or changing tested behavior; also the generator discipline in a loop. NOT for trivial edits, no-behavior constants, spikes, or docs.