Written to /Users/dannote/Development/quickbeam/context.md.
Summary of findings:
- 214 total WPT test scenarios across 19 files
- 49 covered (23%), 17 partially covered (8%), 149 not covered (70%)
Biggest gaps:
- Blob constructor — 26/28 scenarios missing (type validation, iterator protocol, ArrayBuffer/typed array parts, options handling, toString coercion)
- Blob.slice() — 21/22 missing (negative indices, cross-part slicing, contentType filtering, double values)
- Blob.bytes() — Entirely untested
- TextDecoder ignoreBOM — Entirely untested
- TextDecoder fatal — 27/37 overlong encoding variants missing
- URL constructor/setters — Need data-driven testing from JSON test data (hundreds of cases vs ~15 hand-picked)
- UTF-16 TextDecoder — All UTF-16 tests (30+ scenarios) blocked on UTF-16 support