When to Use Use this skill when: - Starting non-trivial changes - Coordinating spec, design, implementation, and validation - Running command-based SDD flow --- Canonical Phase Order 1. - understand existing behavior and constraints 2. - define intent and scope 3. - implement tasks from approved plan 4. - validate behavior against spec and regressions 5. - capture completion and close loop Never skip a phase without explicit rationale. --- Artifacts per Phase - Explore: findings and risks - Propose: change proposal with scope boundaries - Apply: code + tests - Verify: evidence of validation -…