Record archive recovery lifecycle and validate receipt provenance

Assistant: codex
Assistant-Model: gpt-6-astra
Assistant-Session: 01a06ecb-456a-71c2-b41e-0755d336e883

scripts/verify_nextcloud_offsite_restore.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 """Silent attended transfer of a real encrypted backup for isolated recovery."""
 import argparse
+from datetime import datetime, timezone
 import base64
 import urllib.request
 import shutil
@@ -70,10 +71,11 @@ def main():
     p.add_argument('--receipt',required=True)
     a=p.parse_args()
     fd=os.open(a.receipt,os.O_WRONLY|os.O_CREAT|os.O_EXCL,0o600)
-    receipt={'schema':'platform.real-offsite-recovery.v1','status':'failed'}
+    receipt={'schema':'platform.real-offsite-recovery.v1','status':'failed','started_at':datetime.now(timezone.utc).isoformat()}
     try: run(a.source,a.directory,receipt)
     except Exception as error: receipt['error']=str(error) if isinstance(error,LaneError) else 'internal_error'
     finally:
+        receipt['finished_at']=datetime.now(timezone.utc).isoformat()
         with os.fdopen(fd,'w') as f: json.dump(receipt,f,indent=2)
     return int(receipt['status']=='failed')