fix(d2): datetime.now(UTC) everywhere + SQLITE-001 automation tests on ephemeral postgres

app/services/backup_service.py

@@ -156,7 +156,7 @@ async def create_backup(
         # Update backup record
         backup.status = "completed"
         backup.size_bytes = size_bytes
-        backup.completed_at = datetime.utcnow()
+        backup.completed_at = datetime.now(UTC)
         await db.flush()
         await db.refresh(backup)
 

app/services/webhook_service.py

@@ -9,6 +9,7 @@ import json
 import logging
 import socket
 import uuid
+from datetime import UTC, datetime
 from typing import Any
 from urllib.parse import urlparse
 
@@ -218,7 +219,7 @@ async def send_webhook(
     body = {
         "event": event_name,
         "payload": payload,
-        "timestamp": __import__("datetime").datetime.utcnow().isoformat() + "Z",
+        "timestamp": datetime.now(UTC).isoformat().replace("+00:00", "Z"),
     }
     body_bytes = json.dumps(body, default=str).encode("utf-8")