fix(jobs): bind completed effects to checkpoints

harness/tests/test_job_runner.py

@@ -145,6 +145,34 @@ def test_nonexistent_well_formed_resume_run_id_is_rejected(tmp_path):
         run_job(_spec(tmp_path).with_resume("a" * 32), [lambda _context: None])
 
 
+@pytest.mark.parametrize("tamper", ["artifact_and_manifest", "spec", "producer"])
+def test_resume_rejects_manifest_root_or_binding_tamper(tmp_path, tamper):
+    def stage(context):
+        artifacts = context.run_dir / "artifacts"
+        artifacts.mkdir()
+        (artifacts / "effect.json").write_text("ok")
+        return StageArtifacts(("effect.json",))
+
+    report = run_job(_spec(tmp_path), [stage])
+    artifacts = tmp_path / ".tht-jobs" / "evidence" / "runs" / report.run_id / "artifacts"
+    manifest_path = artifacts / "artifact-manifest.json"
+    manifest = json.loads(manifest_path.read_text())
+    if tamper == "artifact_and_manifest":
+        (artifacts / "effect.json").write_text("evil")
+        digest = __import__("hashlib").sha256(b"evil").hexdigest()
+        manifest["stages"]["stage"]["files"]["effect.json"] = {
+            "sha256": digest, "size": 4,
+        }
+    elif tamper == "spec":
+        manifest["spec_fingerprint"] = "sha256:" + "0" * 64
+    else:
+        manifest["stages"]["other"] = manifest["stages"].pop("stage")
+    manifest_path.write_text(json.dumps(manifest, sort_keys=True, separators=(",", ":")) + "\n")
+
+    with pytest.raises(CorruptCheckpointError, match="artifact"):
+        run_job(_spec(tmp_path).with_resume(report.run_id), [stage])
+
+
 def test_successful_job_is_idempotently_resumable(tmp_path):
     calls = []