feat(rates): last-mile rate rules with bulk per-ton-km and container distance bands

- rates: min_km/max_km columns, PER_TON_KM unit, ETB|USD currency for last mile
- extend UQ_rates_pattern with band start; overlap + shape validation
- shared last-mile charge resolver; approve-dialog price estimate endpoint
- delivery-fee invoice prices via rules, falls back to vehicle price/km
- backoffice: last-mile rate form (mode, container type, band, currency)

apps/edr-freight-api/src/modules/rule-engine/repositories/rates.repository.ts

@@ -74,6 +74,7 @@ export class RatesRepository implements IRatesRepository {
     tradeDirection?: string | null;
     originYardId?: string | null;
     destinationYardId?: string | null;
+    minKm?: number | null;
   }): Promise<Rate | null> {
     const qb = this.repo
       .createQueryBuilder('rate')
@@ -111,6 +112,13 @@ export class RatesRepository implements IRatesRepository {
     } else {
       qb.andWhere('rate.destination_yard_id IS NULL');
     }
+    // Band start distinguishes sibling last-mile bands, mirroring the
+    // COALESCE(min_km, -1) column of UQ_rates_pattern.
+    if (pattern.minKm !== null && pattern.minKm !== undefined) {
+      qb.andWhere('rate.min_km = :minKm', { minKm: pattern.minKm });
+    } else {
+      qb.andWhere('rate.min_km IS NULL');
+    }
 
     return qb.getOne();
   }