Fix ROCm diffusion CI platform guard and startup deadlines

Signed-off-by: Sy03 <1370724210@qq.com>

tests/diffusion/models/magi2/test_native_compile_cuda.py

@@ -14,12 +14,17 @@ from tests.diffusion.models.magi2.test_native_packing import (
 )
 from tests.helpers.mark import hardware_marks
 from vllm_omni.diffusion.models.magi2.sampler_magi2 import CFGConfig
+from vllm_omni.platforms import current_omni_platform
 
 pytestmark = [
     pytest.mark.diffusion,
     pytest.mark.core_model,
     *hardware_marks(res={"cuda": "L4"}, num_cards=1),
-    pytest.mark.skipif(not torch.cuda.is_available(), reason="requires CUDA"),
+    # ROCm also exposes torch.cuda, but this path uses vLLM CUDA FlashAttention.
+    pytest.mark.skipif(
+        not current_omni_platform.is_cuda() or not torch.cuda.is_available(),
+        reason="requires vLLM CUDA FlashAttention",
+    ),
 ]