Add GPU preflight Makefile target

Makefile

@@ -1,4 +1,4 @@
-.PHONY: install validate config artifacts smoke sft dpo all evaluate demo
+.PHONY: install validate config artifacts preflight smoke sft dpo all evaluate demo
 
 install:
 	pip install -r requirements.txt
@@ -14,6 +14,9 @@ config:
 artifacts:
 	python scripts/check_artifacts.py
 
+preflight:
+	python scripts/preflight_gpu.py
+
 smoke:
 	python scripts/smoke_test.py