ci(test): display custom error message if tampered/missing verification fails

Author: Clément Turmel

immutables_verification_error-1757423162.json

@@ -0,0 +1,11 @@
+{
+  "immutables_dir": "db/immutable",
+  "missing-files": [
+    "00001.chunk",
+    "00001.primary",
+    "00001.secondary"
+  ],
+  "non-verifiable-files": [],
+  "tampered-files": [],
+  "timestamp": "2025-09-09T13:06:02.845750343+00:00"
+}