Add support for new models and fix GitHub issues

- Add Gemma3n model support with text generation capabilities
- Add new CUDA mean operations for improved performance
- Add macOS documentation and performance tests
- Update LLAMA patches for ROCm/CUDA compatibility
- Fix various model conversion and processing issues
- Update CI workflows and build configurations
- Add library model tests and Shakespeare test data

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

fs/gguf/gguf.go

@@ -65,7 +65,7 @@ func Open(path string) (f *File, err error) {
 		return nil, err
 	}
 
-	if f.Version != 3 {
+	if f.Version < 2 {
 		return nil, fmt.Errorf("%w version %v", ErrUnsupported, f.Version)
 	}