Replace git-tag-triggered container builds with path-based triggers on
main and workflow_dispatch. Tags now encode the upstream app version and
commit SHA (vX.Y.Z-<sha>) for full traceability. The manual
container-tag-and-release task is replaced by container-build-and-release
which dispatches workflows via the Forgejo API.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>