feat(wagons): filter list by last-maintenance date range

Adds maintenanceFrom/maintenanceTo to ListWagonsQueryDto and applies them
in WagonsService.buildListQuery as a correlated subquery against
wagon_status_logs (last flip to MAINTENANCE), mirroring the existing
createdFrom/createdTo range filter. Both ends inclusive, whole days.

apps/edr-freight-api/src/modules/wagons/dto/list-wagons-query.dto.ts

@@ -91,4 +91,18 @@ export class ListWagonsQueryDto {
   @IsOptional()
   @IsDateString()
   createdTo?: string;
+
+  @ApiPropertyOptional({
+    description: 'Last maintenance flip on or after this day (YYYY-MM-DD)',
+  })
+  @IsOptional()
+  @IsDateString()
+  maintenanceFrom?: string;
+
+  @ApiPropertyOptional({
+    description: 'Last maintenance flip on or before this day (YYYY-MM-DD)',
+  })
+  @IsOptional()
+  @IsDateString()
+  maintenanceTo?: string;
 }

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

@@ -90,6 +90,27 @@ export class WagonsService {
       });
     }
 
+    // Last-maintenance range, both ends inclusive. There's no column to
+    // compare directly — "last maintenance" is the latest status-log flip to
+    // MAINTENANCE (see attachStatusDates below), so this mirrors that same
+    // MAX(...) FILTER(...) as a correlated subquery against the same table.
+    if (query.maintenanceFrom) {
+      qb.andWhere(
+        `(SELECT MAX(l.created_at) FROM freight.wagon_status_logs l
+            WHERE l.wagon_id = w.id AND l.to_status = '${WagonStatus.Maintenance}')
+          >= CAST(:maintenanceFrom AS date)`,
+        { maintenanceFrom: query.maintenanceFrom },
+      );
+    }
+    if (query.maintenanceTo) {
+      qb.andWhere(
+        `(SELECT MAX(l.created_at) FROM freight.wagon_status_logs l
+            WHERE l.wagon_id = w.id AND l.to_status = '${WagonStatus.Maintenance}')
+          < CAST(:maintenanceTo AS date) + INTERVAL '1 day'`,
+        { maintenanceTo: query.maintenanceTo },
+      );
+    }
+
     // Search matches the wagon number or either run number.
     if (search) {
       qb.andWhere(