cloud: production gaps (worker loop + true cancel, task result columns + migration, DB interface migration, metrics + backup)

cloud/cost.py

@@ -10,6 +10,7 @@ so estimates are never mixed into actual totals.
 
 import os
 import sqlite3
+from cloud.db import connect as _db_connect
 import time
 from datetime import datetime, timezone
 
@@ -56,7 +57,7 @@ class CostStore:
         if db_path != ":memory:":
             parent = os.path.dirname(os.path.abspath(db_path))
             os.makedirs(parent, exist_ok=True)
-        self._conn = sqlite3.connect(db_path)
+        self._conn = _db_connect(db_path)
         self._conn.execute(
             """CREATE TABLE IF NOT EXISTS cost_records (
                 id INTEGER PRIMARY KEY AUTOINCREMENT,