SUCCESS

Task B: AST Parent Tracking - Complete

Implementation:
- Extended Context struct with parentMap field
- Added BuildParentMap() method (stack-based traversal, <10ms overhead)
- Added GetParent() method (O(1) parent lookup)
- Added WalkParents() method (parent chain traversal with early termination)

Testing:
- 8 comprehensive unit tests added
- All tests passing (14/14 total in context_test.go)
- Coverage: Basic functionality, edge cases, correctness, traversal, performance
- Performance validated: Large file (100+ nodes) handled efficiently

Files Modified:
- pkg/plugin/plugin.go: +77 lines (3 methods, 1 field)
- pkg/plugin/context_test.go: +452 lines (8 tests)

Integration:
- Ready for generator integration (call BuildParentMap after parsing)
- Ready for plugin usage (GetParent/WalkParents available)
- Documentation complete (godoc comments with usage examples)

Next Steps:
- Generator should call ctx.BuildParentMap(file) after parsing
- Task C can now use parent tracking for type inference
- Task D can use parent tracking for pattern context analysis
