speccy-decompose

Decompose a Speccy SPEC into a checklist of agent-sized tasks (`TASKS.md`), or reconcile the list after a SPEC was amended. Use when the user says "break the spec into tasks", "generate tasks for SPEC-NNNN", "decompose this spec", or when the task list looks stale relative to the SPEC. Requires: an existing `SPEC.md`. If no `SPEC.md` → prefer speccy-plan to draft one first. Do NOT trigger as part of a SPEC amendment — speccy-amend reconciles TASKS.md.