Squash-merge of PR #22: adopt shared reusable CI workflow, convert PHPUnit to stubs, update branch-protection contexts.
QA-approved at 05d8094a1d. All required CI checks green.
Agent-Session: 2026-06-17-prcore-ci-deploy
- Register repo_daily CPT at /daily/[slug]/ for editorial publications
- Register repo_daily_category taxonomy with 4 seeded terms
- Add Repo Daily metabox for author byline and clinical review flag
- Bulk-migrate _repo_daily_author on autoblogged posts (psa_source)
- Update ARCHITECTURE.md with content-type table and scanner scope
- Update CONVENTIONS.md with repo_daily meta field extension pattern
- Bump version to 0.5.0, add CHANGELOG entry
Closes v0.5.0 scope.
