Introduce a manual re-dispatch workflow and wire automatic dispatch from releases to the Docker workflow. dispatch-docker-release.yml was converted to a workflow_dispatch-based "Re-dispatch Docker Release" that accepts snowluma_tag, docker_image_override and platforms_override inputs and forwards them (plus source repository) to the downstream docker-image.yml in the Docker release repo. release.yml gains a dispatch-docker job that runs after the release job and uses a PAT to invoke the same downstream workflow for newly published tags. These changes let maintainers rebuild Docker images for existing tags (e.g. to fix Dockerfile issues or rotate credentials) without re-tagging, and ensure the downstream dispatch runs under the configured token.