SUCCESS

None Context Inference Plugin implemented and tested.

Files created:
- pkg/plugin/builtin/none_context.go (400 lines)
- pkg/plugin/builtin/none_context_test.go (200 lines)
- tests/golden/option_06_none_inference.dingo (integration test)

Test results:
- Unit tests: 8 passing, 1 skipped (expected)
- All core functionality working:
  * Return statement context ✓
  * Explicit type annotation ✓
  * Error on ambiguity ✓
  * AST transformation ✓
  * Type name extraction ✓

Implementation complete:
- Discovery phase: finds None identifiers
- Transform phase: infers types from context
- Error handling: reports ambiguous None
- go/types integration: uses TypesInfo for accuracy
- Parent tracking: uses WalkParents from Task B

Ready for integration:
- Plugin can be registered in generator pipeline
- Golden test ready for end-to-end validation
- Documentation complete (changes.md, notes.md)

Next steps:
- Generator should register NoneContextPlugin after OptionTypePlugin
- Run golden test: go test ./tests -run TestGoldenFiles/option_06 -v
