docs: mark cache versioning as complete

Author: claude

CODE_REVIEW.md

@@ -512,7 +512,7 @@ The README is comprehensive with:
 
 4. ✅ **FIXED: Replace `unwrap()` calls with proper error handling** - Fixed in `cache.rs` with proper match/warning pattern
 5. ✅ **FIXED: Add documentation for public API** - Added comprehensive doc comments to core types in `types.rs`
-6. Implement cache versioning/migration
+6. ✅ **FIXED: Implement cache versioning/migration** - Added `CACHE_VERSION` constant, automatic rebuild on version mismatch
 7. ✅ **FIXED: Add recursion depth limit to `find_codeowners_files`** - Added `MAX_RECURSION_DEPTH = 100` constant
 
 ### Medium Priority
@@ -553,10 +553,10 @@ All critical and high-priority issues have been addressed:
 4. ✅ **User Experience:** Added `--quiet` flag for scripting/CI usage
 5. ✅ **Documentation:** Comprehensive doc comments added to public types
 6. ✅ **Code Quality:** Module visibility already well-organized (verified)
+7. ✅ **Forward Compatibility:** Cache versioning with automatic rebuild on format changes
 
 Remaining improvements (low priority):
-- Implement cache versioning/migration
-- Refactor duplicate tag parsing logic (owner parsing already shared)
+- Refactor duplicate tag parsing logic (owner parsing already shared via `parse_owner`)
 
 The codebase now follows Rust best practices with no panics in library code, comprehensive error handling, and 100 passing tests (77 unit + 23 integration). The tool is production-ready for enterprise use.