Background: post-2026-05-06 SCM is Gitea, not GitHub. Gitea 1.22.6 has
no repository_dispatch / workflow_dispatch trigger API (empirically
verified across 6 candidate paths in molecule-core#20 issuecomment-913).
The molecule-core/publish-runtime.yml cascade therefore cannot fire
templates via curl-dispatch — pivots to push-mode instead.
This PR is the consumer side of that pivot:
- .runtime-version file at repo root — single line, plain version
string. Currently 0.1.129 (latest published as of 2026-05-07).
publish-runtime overwrites this on each cascade.
- publish-image.yml gains a resolve-version job that reads the file
and forwards the value to the reusable build workflow as the
third-priority source in the resolution chain.
Sequencing context: this PR (and 8 sibling PRs to the other template
repos) MUST land before molecule-core#20 v2 is merged.
Refs molecule-core#14, molecule-core#20.
