tmu
3df672d306
A release pushes main and then a tag pointing at the same commit, so
the branch run re-verifies the identical SHA the tag run already
verifies (and publishes). Add a cheap release-gate job that recognizes
the '🔖 Release x.y.z' commit message on main and skips the
full build/maintain jobs; tag, PR, and ordinary main pushes are
unaffected, and the gate fails open (runs CI) if it errors.