All self::CONST refs in renderer pointed at constants that only exist on
PR_Core_Settings. PR #22 split the renderer into its own class but omitted
the constants. Promote 6 option-key private consts to public on
PR_Core_Settings; update renderer to reference them as PR_Core_Settings::*.
Closes #(no issue). Regression introduced in v0.7.0 (#22).
Agent-Session: 2026-06-17-prcore-500fix
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
