fix(backup): log missing db config instead of raising

- Use module logger in backup/db.py
- Skip db dump when no databases.csv entry is present
- Apply black/formatting cleanup across backup/restore/tests

https://chatgpt.com/share/69519d45-b0dc-800f-acb6-6fb8504e9b46

src/baudolo/backup/cli.py

@@ -2,7 +2,7 @@ from __future__ import annotations
 
 import argparse
 import os
-from pathlib import Path
+
 
 def parse_args() -> argparse.Namespace:
     dirname = os.path.dirname(__file__)
@@ -25,7 +25,7 @@ def parse_args() -> argparse.Namespace:
 
     p.add_argument(
         "--repo-name",
-        default='backup-docker-to-local',
+        default="backup-docker-to-local",
         help="Backup repo folder name under <backups-dir>/<machine-id>/ (default: git repo folder name)",
     )
     p.add_argument(