SUCCESS

Pattern Match Plugin fully implemented with exhaustiveness checking.

Files Created:
- pkg/plugin/builtin/pattern_match.go (410 lines)
- pkg/plugin/builtin/pattern_match_test.go (503 lines)
- tests/golden/pattern_match_02_exhaustive.dingo (64 lines)

Tests: 10/10 passing (18 subtests)

Features:
✅ Discovery of match expressions via DINGO_MATCH_START markers
✅ Pattern extraction via DINGO_PATTERN markers
✅ Exhaustiveness checking for Result<T,E> and Option<T>
✅ Wildcard pattern support
✅ Expression mode detection (parent tracking)
✅ Compile error generation for non-exhaustive matches
✅ Two-level type inference (scrutinee name + pattern-based fallback)
✅ Position-based comment matching (handles multiple matches)

Ready for integration.
