feat: display vehicle name instead of ID in fuel purchases table

Backend:
- FuelService.getAllFuelPurchases() now loads vehicle relationship
- Uses leftJoinAndSelect to eagerly load Vehicle data
- Returns complete FuelPurchase with nested vehicle object

Frontend:
- Table displays vehicle.registrationNumber (primary)
- Falls back to vehicle.plateNumber if registration unavailable
- Falls back to vehicleId as last resort

Better UX: shows human-readable vehicle info instead of UUID.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

apps/edr-freight-api/src/modules/fuel/fuel.service.ts

@@ -31,7 +31,11 @@ export class FuelService {
   }
 
   async getAllFuelPurchases(): Promise<FuelPurchase[]> {
-    return this.purchaseRepository.find({ order: { purchaseDate: 'DESC' } });
+    return this.purchaseRepository
+      .createQueryBuilder('purchase')
+      .leftJoinAndSelect('purchase.vehicle', 'vehicle')
+      .orderBy('purchase.purchaseDate', 'DESC')
+      .getMany();
   }
 
   async getFuelPurchases(

apps/edr-freight-web/backoffice/src/pages/fleet/FuelPurchasePage.tsx

@@ -199,7 +199,7 @@ export default function FuelPurchasePage() {
           <Table.Tbody>
             {(purchasesData as FuelPurchase[])?.map((purchase) => (
               <Table.Tr key={purchase.id}>
-                <Table.Td>{purchase.vehicleName || purchase.vehicleId}</Table.Td>
+                <Table.Td>{(purchase as any).vehicle?.registrationNumber || (purchase as any).vehicle?.plateNumber || purchase.vehicleId}</Table.Td>
                 <Table.Td>{new Date(purchase.purchaseDate).toLocaleDateString()}</Table.Td>
                 <Table.Td align="right">{Number(purchase.liters).toFixed(2)}</Table.Td>
                 <Table.Td align="right">ETB {Number(purchase.costPerLiter).toFixed(2)}</Table.Td>