feat: deploy.sh — one-command agent rollout over SSH (+ README guide) ...

deploy.sh per host: create panel server entry (reuse existing,
--recreate for a fresh key) -> scp agent files -> install.sh via sudo ->
wait for first packet. Non-interactive and idempotent, designed for
AI-agent-driven deploys; README includes a ready-made prompt.

Co-Authored-By: Claude Code <noreply@anthropic.com>