feat(phase5): polish + deployment
- skill/SKILL.md: rewritten to 9 lines — 'status is automatic'
- deploy-to-agents.sh: no AGENTS.md injection; deploys hook + npm install
- install.sh: clean install flow; prints required env vars
- deploy/status-watcher.service: systemd unit file
- deploy/Dockerfile: containerized deployment (node:22-alpine)
- src/live-status.js: deprecation warning + start-watcher/stop-watcher pass-through
- README.md: full docs (architecture, install, config, upgrade guide, troubleshooting)
- make check: 0 errors, 0 format issues
- npm test: 59 unit + 36 integration = 95 tests passing
835faa0eab