feat: Add currency and unit support across models, routes, and templates; enhance UI for consumption, costs, and production

tests/unit/test_consumption.py

@@ -25,6 +25,8 @@ def test_create_consumption(client: TestClient) -> None:
         "scenario_id": scenario_id,
         "amount": 125.5,
         "description": "Fuel usage baseline",
+        "unit_name": "Liters",
+        "unit_symbol": "L",
     }
 
     response = client.post("/api/consumption/", json=payload)
@@ -34,6 +36,7 @@ def test_create_consumption(client: TestClient) -> None:
     assert body["scenario_id"] == scenario_id
     assert body["amount"] == pytest.approx(125.5)
     assert body["description"] == "Fuel usage baseline"
+    assert body["unit_symbol"] == "L"
 
 
 def test_list_consumption_returns_created_items(client: TestClient) -> None:
@@ -46,6 +49,8 @@ def test_list_consumption_returns_created_items(client: TestClient) -> None:
                 "scenario_id": scenario_id,
                 "amount": amount,
                 "description": f"Consumption {amount}",
+                "unit_name": "Tonnes",
+                "unit_symbol": "t",
             },
         )
         assert response.status_code == 201