Deploy convention at M.Video: a release-* branch push deploys to stage and a
v* tag push deploys to PROD. The old guard only matched release/* (slash) and
never caught tag pushes, so a prod deploy could run unconfirmed.
- permission-gate: match main/master, release-[-/], --tags/--follow-tags, and
whitespace-preceded v<digit> tags; false-positive-safe (space discriminator)
- create-mr.sh: refuse source branch release-* (not just release/*)
- jira-workflow doc updated to release-*
Verified with a behavioral test suite (10 cases incl. v2, false-positive checks).