Create a shared PR-title / conventional-commit policy

The goal of the issue is to create a reusable workflow with types/scopes inputs and an org default.

The types list would be a community decision whereas the mechanism would belong in the testing repo.

Start by inspecting the testing repository's existing workflow configuration and the issue's proposal for a reusable workflow. Clarify the community-approved types and scopes, then define the org default; the work is done when the reusable PR-title/conventional-commit policy accepts those inputs and the default is documented or configured.

Written by the indexing model from the issue text.