Document the per-module preprocessing solution for coverage.
Initial CBOR coverage: 87.50% (203/232 points)
- RFC 7049/8949 test vectors
- Property-based roundtrip tests
- Edge case tests
Coverage collection working on:
- 100% of CBOR module
- ~93% of core modules (41/44, excluding cpp-dependent modules)
See COVERAGE_SETUP.md for usage instructions.