chore: Set up OpenClaw gateway in sandboxes
Install pm2 and expose gateway port 18789 in Dockerfile. Add
setupOpenClaw helpers for Cloudflare, Daytona, Deno and Vercel that
write OpenClaw config/auth files, start the gateway (pm2 or background
command), and log status. Add SANDBOX_ROOT, OPENCLAW_CONFIG and
OPENCLAW_AUTH_PROFILES to runtime types and ProcessEnv. Add envalid to
dependencies, update snapshots, keep sandboxes running, and add SIGINT
handlers for graceful shutdown.