Service skill — decides which test kinds (Jest, PHPUnit, integration, E2E Playwright, CLI bash smoke, visual, a11y, API contract, perf, security, manual QA, migration, smoke RED) make sense for a given gaad-* plan. Used by gaad-plan-new / gaad-plan-amend / gaad-plan-extend / gaad-plan-clone / gaad-plan-discover to avoid planning tasks for test kinds that have no surface in the feature. Trigger when user says "test matrix", "applicability", "które testy mają sens", "re-evaluate test matrix", "/gaad-test-matrix", or when a plan-* skill needs to consult or refresh `.test-matrix.md`.
