Run the brainstorming superpower overnight

overnight-brainstorm.sh

cat > ~/.claude/skills/overnight-brainstorm/SKILL.md << 'EOF'
---
name: overnight-brainstorm
description: Defer brainstorming and speccing to run at 1am via system cron. Runs even if Claude Code is closed.
argument-hint: [feature or topic to brainstorm and spec]
allowed-tools: Bash, Write
---

## Purpose
Schedule an autonomous overnight brainstorm using system cron so it runs at 1am regardless of whether Claude Code is open.

## Steps

1. Parse `$ARGUMENTS` as the feature or topic to spec.
2. Generate a slug from it (lowercase, hyphens, no special characters).
3. Set the output path to `~/claude-overnight/<slug>-<YYYY-MM-DD>.md`.
4. Create the `~/claude-overnight/` directory if it doesn't exist.
5. Write a one-shot shell script to `~/.claude/overnight-jobs/<slug>.sh` containing:
   - The `claude -p` headless command with the full brainstorm prompt below
   - Output redirected to the output file
   - A line at the end that removes itself from crontab after firing (so it's truly one-shot)
6. Add a crontab entry: `0 1 * * * ~/.claude/overnight-jobs/<slug>.sh`
7. Confirm to the user: what will run, when, the output path, and that it will fire even with Claude Code closed.

## The claude -p prompt to use