The MSRV check gate (rust:1.78-slim build) was already fully
implemented in the initial CI workflow. This verification note
documents the existing implementation and confirms all acceptance
criteria are met.
Acceptance criteria:
- Gate runs in pdftract-ci on every PR: PASS
- Failure blocks PR merge: PASS
- Successful run reports artifact: PASS
- Failure mode produces actionable error: PASS
No changes to the workflow were required.
Related: pdftract-2rf (quality gates coordinator)
