Mirrors redeploy.sh conventions (pinned host key, DEPLOY_PASS/deploy.secret/
prompt password resolution, plink discovery). Uploads the three electron-builder
artifacts via pscp to a temp dir, then docker cp's them into the app container's
/data/downloads (volume-path-independent), and verifies the public feed serves
the new version. Keeps older versions; only latest.yml is overwritten.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
