- Add c8 coverage tooling and test:coverage script
- Register previously unused DocumentLinkProvider and ReferenceProvider
- Add test-assets.test.ts using sdk/test-assets for testing
- Add coverage-boost.test.ts with comprehensive provider tests
- Add instance-coverage.test.ts for instance document validation
- Add test fixtures for various schema types
- Total: 192 tests passing, 83.89% statement coverage