* ci(helm): add OCI chart release workflow
Publishes the Helm chart to ghcr.io/nvidia/openshell/helm-chart via helm push on every tag (versioned + :latest) and main push (:0.0.0-dev overwrite + :0.0.0-dev.<sha> per-commit pin). Renames Chart.yaml name to helm-chart to match the target OCI path.
* ci(helm): use full sha in dev pinned chart version
The container images pushed by docker-build.yml are tagged with the
full $GITHUB_SHA, not a 7-char prefix. Match the chart's pinned
version (0.0.0-dev.<full-sha>) so the chart tag and the image tag
the chart resolves to are identical.
* docs(readme): add helm chart install instructions
Document the OCI chart at ghcr.io/nvidia/openshell/helm-chart with
examples for tagged, floating dev, and SHA-pinned dev installs, and
flag the Kubernetes deployment path as experimental.
* docs(helm): split chart details into chart README
Move the dev tag conventions and configuration pointers into a new
README under deploy/helm/openshell/ and shorten the top-level README
section to the install command (no --version, defaults to latest
tagged semver) plus a link to the chart README.
Taylor Mutch