fix(surgery): guard unvalidated Qwen hybrid layouts

tests/conditional/test_model_download_runtime.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import os
 import uuid
 
 import pytest
@@ -17,6 +18,7 @@ MODEL = "hf-internal-testing/tiny-random-gpt2"
 REVISION = "71034c5d8bde858ff824298bdedc65515b97d2b9"
 MISTRAL4_MODEL = "mistralai/Mistral-Small-4-119B-2603"
 MISTRAL4_REVISION = "a11f36bebf709121056b1dbcc943d1c6afbe494d"
+QWEN38_MODEL = "Qwen/Qwen3.8-27B"
 
 
 def test_pinned_tiny_model_download_inference_and_offline_cache(monkeypatch):
@@ -71,3 +73,26 @@ def test_pinned_mistral4_config_resolves_composite_contract_without_remote_code(
     assert profile.model_type == "mistral4"
     assert profile.arch_class is ArchitectureClass.LARGE_MOE
     assert (profile.num_experts, profile.num_active_experts) == (128, 4)
+
+
+@pytest.mark.gpu
+def test_qwen38_bf16_pristine_baseline_blocks_unvalidated_surgery(tmp_path):
+    """Operator-gated 27B regression: healthy stock model, zero modified weights."""
+    if os.environ.get("OBLITERATUS_QWEN38_E2E") != "1":
+        pytest.skip("set OBLITERATUS_QWEN38_E2E=1 on a >=80 GiB GPU runner")
+
+    from obliteratus.abliterate import AbliterationPipeline, PipelineValidationError
+
+    pipeline = AbliterationPipeline(
+        QWEN38_MODEL,
+        output_dir=str(tmp_path / "qwen38-output"),
+        dtype="bfloat16",
+        quantization=None,
+    )
+    pipeline._summon()
+    pipeline._capture_stock_baseline()
+    assert pipeline._stock_baseline["perplexity"] > 0
+    assert pipeline._stock_baseline["coherence"] > 0
+    with pytest.raises(PipelineValidationError, match="no validated projection allowlist"):
+        pipeline._validate_architecture_surgery_support()
+    assert pipeline._excise_modified_count is None