Fix CI timezone and fresh settings initialization

backend/tests/test_settings_api.py

@@ -1,5 +1,11 @@
 from app import commands
 from app.main import _validate_settings
+from app.migrations import _normalize_timezone
+
+
+def test_system_timezone_absolute_utc_is_normalized():
+    assert _normalize_timezone("/UTC") == "UTC"
+    assert _normalize_timezone("/usr/share/zoneinfo/Europe/Berlin") == "Europe/Berlin"
 
 
 def test_plain_onedrive_remote_is_accepted(monkeypatch):