unseen-eval groups 4-6: generic AX batch dispatcher (engine_trace on it), replay task and image stage, scorer with adoption gate

Implemented with Codex.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

tests/test_unseen_image.py

@@ -0,0 +1,16 @@
+"""Static image contract; no Docker invocation."""
+
+import hashlib
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+ENGINE_SHA = "06ec67d411cd7abbfcd0735b1c2a70e4f3eb65ddcfeef89975709c664f59ad42"
+
+
+def test_image_stages():
+    text = (ROOT / "plane/Dockerfile.engine-task").read_text()
+    engine, replay = text.split("FROM engine AS replay", 1)
+    original = engine.replace("v0.3.1 AS engine", "v0.3.1").rstrip() + "\n"
+    assert hashlib.sha256(original.encode()).hexdigest() == ENGINE_SHA
+    assert "FROM ghcr.io/norandom/ax-task-runner:v0.3.1 AS engine" in engine
+    assert "git" in replay and "replay_entry.py" in replay and "ousast pre-push --help" in replay