brainstorm-server-env-isolation-for-concurrent-sessions

The obra/superpowers brainstorming visual companion server (skills/brainstorming/scripts/server.cjs) uses SCREEN_DIR per process and supports BRAINSTORM_PORT, BRAINSTORM_DIR, and BRAINSTORM_HOST env vars for isolation. Deployed as a persistent systemd service on port 17777 with a shared screen_dir; screen artifacts auto-cleanse after 24h via session-close hook and after 7d via daily cron at 04:00.