feat: integrate ownership-costs UI into vehicle detail pages (refs #15)

- Add OwnershipCostsList to desktop VehicleDetailPage
- Add OwnershipCostsList to mobile VehicleDetailMobile
- Users can now view, add, edit, and delete recurring costs directly
  from the vehicle detail view

frontend/src/features/vehicles/mobile/VehicleDetailMobile.tsx

@@ -11,6 +11,7 @@ import { FuelLogResponse, UpdateFuelLogRequest } from '../../fuel-logs/types/fue
 import { FuelLogEditDialog } from '../../fuel-logs/components/FuelLogEditDialog';
 import { fuelLogsApi } from '../../fuel-logs/api/fuel-logs.api';
 import { VehicleImage } from '../components/VehicleImage';
+import { OwnershipCostsList } from '../../ownership-costs';
 
 interface VehicleDetailMobileProps {
   vehicle: Vehicle;
@@ -225,6 +226,14 @@ export const VehicleDetailMobile: React.FC<VehicleDetailMobileProps> = ({
         </Card>
       </Section>
 
+      <Section title="Recurring Costs">
+        <Card>
+          <CardContent>
+            <OwnershipCostsList vehicleId={vehicle.id} />
+          </CardContent>
+        </Card>
+      </Section>
+
       <Section title="Vehicle Records">
         <Box sx={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', mb: 1 }}>
           <Typography variant="body2" color="text.secondary">

frontend/src/features/vehicles/pages/VehicleDetailPage.tsx

@@ -22,6 +22,7 @@ import { FuelLogEditDialog } from '../../fuel-logs/components/FuelLogEditDialog'
 import { FuelLogForm } from '../../fuel-logs/components/FuelLogForm';
 // Unit conversions now handled by backend
 import { fuelLogsApi } from '../../fuel-logs/api/fuel-logs.api';
+import { OwnershipCostsList } from '../../ownership-costs';
 
 const DetailField: React.FC<{
   label: string;
@@ -364,6 +365,11 @@ export const VehicleDetailPage: React.FC = () => {
 
         <Divider sx={{ my: 4 }} />
 
+        {/* Recurring Ownership Costs */}
+        <OwnershipCostsList vehicleId={vehicle.id} />
+
+        <Divider sx={{ my: 4 }} />
+
         <Box sx={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', mb: 2 }}>
           <Typography variant="h6" sx={{ fontWeight: 600 }}>
             Vehicle Records