feat: Consolidate user, role, and theme settings tables into a single migration file

tests/unit/test_setup_database.py

@@ -46,6 +46,7 @@ def test_seed_baseline_data_dry_run_skips_verification(
     assert namespace_arg.dry_run is True
     assert namespace_arg.currencies is True
     assert namespace_arg.units is True
+    assert namespace_arg.theme is True
     assert seed_run.call_args.kwargs["config"] is setup_instance.config
     verify_mock.assert_not_called()
 
@@ -67,6 +68,7 @@ def test_seed_baseline_data_invokes_verification(
     assert isinstance(namespace_arg, argparse.Namespace)
     assert namespace_arg.dry_run is False
     assert seed_run.call_args.kwargs["config"] is setup_instance.config
+    assert namespace_arg.theme is True
     verify_mock.assert_called_once_with(
         expected_currency_codes=expected_currencies,
         expected_unit_codes=expected_units,