Molecule checks for a requirements file at the scenario's default path
before it installs anything, and warns "Missing roles requirements file"
when it is absent - so `requirements-file` pointing elsewhere was silently
ignored and the galaxy roles were never installed. CI failed on a missing
ansible-role-docker; the local run passed only because those roles were
already in ~/.ansible/roles from earlier work, which is exactly the kind of
difference a clean CI run exists to expose.

A symlink satisfies Molecule's check while keeping one copy of the pins.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>