spec-decomposelisted

# spec-decompose — Turn an approved spec into gsd phase plans ## Host dispatch contract - Codex: `$skill`, Codex collaboration roles, and GPT-5.6 tiers. - Claude: `/skill`, Agent/Skill tools, and Claude aliases. - A bare `/skill` in this shared source denotes the Claude form; Codex dispatches the same named skill as `$skill`. ## When to invoke - After `/speckit.plan` writes `specs/NNN/plan.md` (or `/plan-decompose` produced one) - "decompose spec NNN", "generate tasks for NNN", "break this into tasks" - Before `/feature-implement` — a seeded, plan-checked `.planning/` project is its input ## Workflow ### Step 1: Resolve target spec ```bash SPEC_ARG="${ARGUMENTS:-}" if [ -z "$SPEC_ARG" ]; then SPEC_ARG=$(git branch --show-current 2>/dev/null | grep -oE '^[0-9]{3}' | head -1) fi [ -z "$SPEC_ARG" ] && { echo "ERROR: no spec ID. Usage: /spec-decompose NNN"; exit 1; } SPEC_DIR=$(find specs -maxdepth 1 -type d -name "${SPEC_ARG%%-*}-*" 2>/dev/null | head -1) [ -z "$SPEC_DIR" ] && { echo "ERROR: specs/${SPEC_ARG}-* not found"; exit 1; } [ -f "$SPEC_DIR/plan.md" ] || { echo "ERROR: $SPEC_DIR/plan.md missing — run /speckit.plan"; exit 1; } ``` ### Step 2: Seed the gsd project (idempotent) If `.planning/PROJECT.md` already exists for this feature, skip to Step 3. Otherwise translate the FFS spec into gsd's planning inputs: - `.planning/PROJECT.md` — what/why from `spec.md` intro + repo context + constraints (worktree discipline, scoped `git add`, never push, shellcheck/ba