fix(config): preserve device identities and storage costs during migration

tests/test_consolidation_config.py

@@ -0,0 +1,30 @@
+"""Contracts required by the combined EOS configuration."""
+import copy
+import pytest
+from pydantic import ValidationError
+from akkudoktoreos.config.configmigrate import migrate_config_data
+from akkudoktoreos.devices.devices import DevicesCommonSettings
+
+
+def test_device_map_supplies_stable_identity():
+    raw = {"batteries": {"house": {"capacity_wh": 12000}}}
+    a = DevicesCommonSettings.model_validate(raw)
+    b = DevicesCommonSettings.model_validate(raw)
+    assert a.batteries["house"].device_id == b.batteries["house"].device_id == "house"
+    assert "house-soc-factor" in a.measurement_keys
+
+
+def test_device_map_rejects_conflicting_identity():
+    with pytest.raises(ValidationError, match="device_id"):
+        DevicesCommonSettings.model_validate({"batteries": {"house": {"device_id": "other"}}})
+
+
+@pytest.mark.parametrize("as_list", [False, True])
+def test_migration_preserves_lcos_and_input(as_list):
+    battery = {"device_id": "house", "capacity_wh": 12000,
+               "levelized_cost_of_storage_kwh": 0.123}
+    raw = {"devices": {"batteries": [battery] if as_list else {"house": battery}}}
+    original = copy.deepcopy(raw)
+    migrated = migrate_config_data(raw)
+    assert migrated.devices.batteries["house"].levelized_cost_of_storage_amt_kwh == 0.123
+    assert raw == original