Add canon reset and reingest guardrails

tests/test_scan_manifest.py

@@ -74,6 +74,43 @@ def test_registry_scan_manifest_writes_default_cache_and_report(tmp_path: Path,
     assert not (cache_dir / "rescan.lock").exists()
 
 
+def test_registry_scan_manifest_disambiguates_normalized_snapshot_names(tmp_path: Path, capsys) -> None:
+    repo_a = _minimal_repo(tmp_path, "vergabe-teilnahme")
+    repo_b = _minimal_repo(tmp_path, "vergabe_teilnahme")
+    manifest = _manifest(
+        tmp_path,
+        [
+            {"slug": "vergabe-teilnahme", "name": "Vergabe Teilnahme", "path": str(repo_a)},
+            {"slug": "vergabe_teilnahme", "name": "Vergabe Teilnahme Alt", "path": str(repo_b)},
+        ],
+    )
+    output_dir = tmp_path / "snapshots"
+
+    assert cli_main(
+        [
+            "registry",
+            "scan-manifest",
+            str(manifest),
+            "--dry-run",
+            "--output-dir",
+            str(output_dir),
+            "--json",
+        ]
+    ) == 0
+
+    summary = json.loads(capsys.readouterr().out)
+    output_paths = [item["output_path"] for item in summary["repositories"]]
+    assert len(output_paths) == 2
+    assert len(set(output_paths)) == 2
+    assert (output_dir / "vergabe-teilnahme-deterministic.discovery.json").is_file()
+    disambiguated = [
+        path
+        for path in output_dir.glob("vergabe-teilnahme-*-deterministic.discovery.json")
+        if path.name != "vergabe-teilnahme-deterministic.discovery.json"
+    ]
+    assert len(disambiguated) == 1
+
+
 def test_registry_scan_manifest_operational_exit_codes_and_lock(tmp_path: Path, capsys) -> None:
     repo = _minimal_repo(tmp_path, "fixture-repo")
     manifest = _manifest(tmp_path, [{"slug": "fixture-repo", "name": "Fixture Repo", "path": str(repo)}])