On tag push, scp the binary to ~/hsa-app/releases/hsa-app-V<tag>/hsa,
repoint the ~/hsa-app/hsa symlink, and restart the user systemd
service. Add deploy/hsa_app.service unit and deploy/INSTALL.md with
host layout, one-time install, deploy, and rollback steps.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
