feat: implement KM-based maintenance scheduling

Add maintenance intervals configuration to track maintenance by kilometers
driven. When a maintenance is marked COMPLETED, automatically calculate and
schedule the next maintenance based on interval + current odometer reading.

Features:
- MaintenanceInterval entity: stores KM/day intervals per vehicle & type
- scheduleNextMaintenance(): creates next SCHEDULED item after completion
- nextDueKm field: tracks when next maintenance is due (in kilometers)
- getDueBoard() queries already support KM-based tracking

Maintenance now "marches forward" based on distance driven, not just dates.
Each vehicle type can have different intervals (e.g., oil every 10k km, tires 50k km).

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

apps/edr-freight-api/src/modules/maintenance/maintenance.module.ts

@@ -2,12 +2,14 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { MaintenanceSchedule } from './entities/maintenance-schedule.entity';
 import { MaintenanceCost } from './entities/maintenance-cost.entity';
+import { MaintenanceInterval } from './entities/maintenance-interval.entity';
 import { WorkOrder } from './entities/work-order.entity';
 import { Part } from './entities/part.entity';
 import { Warranty } from './entities/warranty.entity';
 import { MaintenanceService } from './maintenance.service';
 import { MaintenanceDepthService } from './maintenance-depth.service';
 import { MaintenanceRepository } from './maintenance.repository';
+import { MaintenanceIntervalRepository } from './maintenance-interval.repository';
 import { WorkOrderRepository } from './work-order.repository';
 import { PartRepository } from './part.repository';
 import { WarrantyRepository } from './warranty.repository';
@@ -16,13 +18,21 @@ import { NotificationInboxModule } from '../notification-inbox/notification-inbo
 
 @Module({
   imports: [
-    TypeOrmModule.forFeature([MaintenanceSchedule, MaintenanceCost, WorkOrder, Part, Warranty]),
+    TypeOrmModule.forFeature([
+      MaintenanceSchedule,
+      MaintenanceCost,
+      MaintenanceInterval,
+      WorkOrder,
+      Part,
+      Warranty,
+    ]),
     NotificationInboxModule,
   ],
   providers: [
     MaintenanceService,
     MaintenanceDepthService,
     MaintenanceRepository,
+    MaintenanceIntervalRepository,
     WorkOrderRepository,
     PartRepository,
     WarrantyRepository,