Agent Skills: evaluate-pr-tests

Evaluates tests added in a PR for coverage, quality, edge cases, and test type appropriateness. Checks if tests cover the fix, finds gaps, and recommends lighter test types when possible. Prefer unit tests over device tests over UI tests. Triggers on: 'evaluate tests in PR', 'review test quality', 'are these tests good enough', 'check test coverage', 'is this test adequate', 'assess test coverage for PR'.