build(refserver): add Dockerfile + release pipeline (Portainer deploy)
Mirrors refapp/refbot: Dockerfile builds the TS image (exposes PORT 3000 +
WS_PORT 3002), scripts/release.js bumps version, tags/pushes git, then builds
and pushes registry.ellite.dev/alpinesystem/refserver:{latest,vX.Y.Z} via the
Portainer Docker API. PORTAINER_STACK_ID gates the redeploy step so the image
is pushed safely before the stack exists; REGISTRY_PASSWORD + PORTAINER_TOKEN
are required for the build/push.