ytstack:grill

Thin wrapper around the vendored superpowers brainstorming skill (vendor/superpowers/skills/brainstorming/SKILL.md). Injects what ytstack already knows (project one-liner, pitch, recent decisions, current milestone), inlines the vendored procedure verbatim, and routes its output into ytstack artifacts instead of a free-floating design doc.

ytstack context (resolved at render time)

# ytstack resolver (M016): checkout = where this shell runs, via the shared lib.
_LIB="${CLAUDE_SKILL_DIR}/../../hooks/lib/git-ctx.sh"
if [ -f "$_LIB" ]; then
  . "$_LIB"; yt_git_ctx "$PWD"; yt_resolve_yt_dir >/dev/null
  _PROJECT_DIR="$YT_TOPLEVEL"; _YT_DIR="$YT_DIR"; _YT_SCOPE="$YT_SCOPE"; _IS_GIT="$YT_IS_GIT"; _PROJECT_KEY="$YT_REPO_KEY"
else
  # Host did not substitute CLAUDE_SKILL_DIR (e.g. Codex adapter): project scope only.
  _IS_GIT=$([ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = true ] && echo yes || echo no)
  _PROJECT_DIR=$(git rev-parse --show-toplevel 2>/dev/null || pwd -P)
  _YT_DIR=""; _YT_SCOPE=none; _PROJECT_KEY=""
  [ -d "$_PROJECT_DIR/.ytstack" ] && { _YT_DIR="$_PROJECT_DIR/.ytstack"; _YT_SCOPE=project; }
fi
cd "$_PROJECT_DIR" 2>/dev/null || true
_PROJECT_SLUG=$(basename "$_PROJECT_DIR")
_M=none; _ONE_LINER=""; _PITCH=none; _DECISIONS=0
if [ -n "$_YT_DIR" ]; then
  [ -f "$_YT_DIR/STATE.md" ] && _M=$(sed -n 's/^current_milestone: *//p' "$_YT_DIR/STATE.md" | head -1)
  [ -f "$_YT_DIR/PROJECT.md" ] && _ONE_LINER=$(sed -n 's/^one-liner: *//p' "$_YT_DIR/PROJECT.md" | head -1)
  _PITCH=$(ls -t "$_YT_DIR"/OFFICE-HOURS*.md 2>/dev/null | head -1); _PITCH=${_PITCH:-none}
  [ -f "$_YT_DIR/DECISIONS.md" ] && _DECISIONS=$(grep -c '^## ' "$_YT_DIR/DECISIONS.md")
fi
[ "$_PITCH" = none ] && [ -f ./OFFICE-HOURS.md ] && _PITCH=./OFFICE-HOURS.md
echo "HAS_YTSTACK: $([ -n "$_YT_DIR" ] && echo yes || echo no)"
echo "CURRENT_MILESTONE: $_M"
echo "ONE_LINER: ${_ONE_LINER:-none}"
echo "PITCH: $_PITCH"
echo "DECISIONS_COUNT: $_DECISIONS"
echo "DESIGN_TARGET: $([ "$_M" != none ] && [ -n "$_YT_DIR" ] && echo "$_YT_DIR/$_M-CONTEXT.md" || echo "${_YT_DIR:-.}/GRILL-<slug>.md")"

ytstack invocation notes

You are invoked to question an idea until it is small and clear enough to plan. The vendored procedure's "Look Before You Ask" step starts from PITCH (the office-hours artifact), ONE_LINER and the last entries of DECISIONS.md: never re-ask what those already answer.

HARD-GATE: none. grill runs with or without .ytstack/; without it, the design notes go to ./GRILL-<slug>.md and the next step is ytstack:office-hours or ytstack:init-project.

Where the vendored text says "design doc", write to DESIGN_TARGET:

• CURRENT_MILESTONE set: append the agreed approach and the rejected alternatives under "Decisions locked in discuss phase" in M###-CONTEXT.md (one dated bullet per decision, YYYY-MM-DD: decided X because Y), and a one-line pointer in DECISIONS.md only for choices that outlive the milestone.
• Otherwise: GRILL-<slug>.md (2-4 word kebab slug) with the same sections; ytstack:plan-milestone reads it as the milestone's goal source.

Where the vendored text says to invoke superpowers:writing-plans, the ytstack equivalent is ytstack:plan-milestone followed by ytstack:slice-milestone; do not invoke them automatically, name them as the next step. The vendored "spike" is fine; a spike's code never lands without a task plan.

Vendored procedure (inlined verbatim)

cat "${CLAUDE_SKILL_DIR}/../../vendor/superpowers/skills/brainstorming/SKILL.md"

Namespace note (ytstack)

The text above is upstream superpowers content (v7.0.2) rendered inside ytstack. Read superpowers:<skill> as ytstack:<skill>; superpowers:writing-plans has no ytstack skill of that name and maps to ytstack:plan-milestone + ytstack:slice-milestone (see the invocation notes). Relative links such as visual-companion.md and builder-check-prompt.md resolve under vendor/superpowers/skills/brainstorming/ in the ytstack plugin directory (${CLAUDE_SKILL_DIR}/../../vendor/superpowers/skills/brainstorming/); read them from there when the procedure asks for them. The scripts/ directory there belongs to the visual companion and is optional.