fix(buun-llama-cpp): isolate fork patch series

The buun build copies the stock llama.cpp backend directory, including patches that target upstream. Remove that copied patch directory before invoking the shared build so only the explicit buun compatibility series is applied to the fork.

Assisted-by: Codex:gpt-5 [systematic-debugging]

Author: localai-org-maint-bot

backend/cpp/buun-llama-cpp/Makefile

@@ -40,6 +40,9 @@ PATCHES_DIR := $(CURRENT_MAKEFILE_DIR)/patches
 define buun-llama-cpp-build
 	rm -rf $(CURRENT_MAKEFILE_DIR)/../buun-llama-cpp-$(1)-build
 	cp -rf $(LLAMA_CPP_DIR) $(CURRENT_MAKEFILE_DIR)/../buun-llama-cpp-$(1)-build
+	# Stock llama.cpp patches target upstream and may not apply to this fork.
+	# The buun-specific compatibility series is applied explicitly below.
+	rm -rf $(CURRENT_MAKEFILE_DIR)/../buun-llama-cpp-$(1)-build/patches
 	$(MAKE) -C $(CURRENT_MAKEFILE_DIR)/../buun-llama-cpp-$(1)-build purge
 	# Augment the copied grpc-server.cpp's KV-cache allow-list with the
 	# fork's turbo2/turbo3/turbo4/turbo2_tcq/turbo3_tcq types and wire up the