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>

llm/memory.go

@@ -151,7 +151,12 @@ func EstimateGPULayers(gpus []discover.GpuInfo, f *ggml.GGML, projectors []strin
 	}
 
 	if graphPartialOffload == 0 {
-		graphPartialOffload = f.KV().GQA() * kvTotal / 6
+		headsKV := f.KV().HeadCountKVMin()
+		if headsKV == 0 {
+			headsKV = 1
+		}
+		gqa := f.KV().HeadCountMax() / headsKV
+		graphPartialOffload = gqa * kvTotal / 6
 	}
 	if graphFullOffload == 0 {
 		graphFullOffload = graphPartialOffload