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_proof.py

@@ -0,0 +1,56 @@
+"""Proof records fail closed using synthetic local results."""
+
+import importlib
+import json
+import sys
+from pathlib import Path
+
+import pytest
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
+p = importlib.import_module("benchmarks.unseen.proof")
+
+
+def test_replay_proof(tmp_path):
+    roots = {}
+    for lane in ("kind", "ax", "vm"):
+        root = tmp_path / lane
+        root.mkdir()
+        roots[lane] = root
+        (root / "inputs.json").write_text("[]")
+        for i in range(5):
+            (root / f"{i}.json").write_text(
+                json.dumps(
+                    {
+                        "input_digest": str(i),
+                        "status": "engine_covered",
+                        "instrument": {"hook_bytes_read": 20, "jvm_wall_seconds": 8, "seconds": 30, "hook_exit": 0},
+                        "push": {"quick_tier": [{"findings": []}]},
+                    }
+                )
+            )
+    assert p.replay_proof(roots)["quick_tier_equal"]
+    path = roots["vm"] / "0.json"
+    record = json.loads(path.read_text())
+    record["instrument"]["jvm_wall_seconds"] = 0
+    path.write_text(json.dumps(record))
+    with pytest.raises(ValueError, match="instrument"):
+        p.replay_proof(roots)
+
+
+def test_engine_proof_counts_differences_without_names(tmp_path):
+    current, baseline = tmp_path / "current", tmp_path / "baseline"
+    current.mkdir()
+    baseline.mkdir()
+    for i in range(2):
+        record = {
+            "repo": "synthetic",
+            "pin": str(i),
+            "done": True,
+            "seconds": 20,
+            "units": [{"unit": str(i), "status": "path", "instrument": {"bytes": 20, "jvm": [{"seconds": 8, "success": True}]}}],
+        }
+        (current / f"{i}.json").write_text(json.dumps(record))
+        (baseline / f"{i}.json").write_text(json.dumps(record))
+    proof = p.engine_proof(current, baseline)
+    assert proof["differences"] == 0 and "synthetic" not in json.dumps(proof)