feat(rule-engine): add fuel surcharge rate trigger and cargo flag

apps/edr-freight-api/src/modules/rule-engine/entities/rate.entity.ts

@@ -24,6 +24,7 @@ export const RATE_TYPES = [
   'RETURN_SURCHARGE',
   'PIL_EXTRA_FEE',
   'CUSTOMS_CLEARANCE',
+  'FUEL_SURCHARGE',
 ] as const;
 
 export type RateType = typeof RATE_TYPES[number];
@@ -41,6 +42,8 @@ export const RATE_UNITS = [
   'PER_KM',
   // Last-mile bulk: price = tons × km × rateValue.
   'PER_TON_KM',
+  // Fuel surcharge only: price = baseLiters × rateValue, once per booking.
+  'PER_LITER',
   'PER_INVOICE',
   'FLAT',
 ] as const;
@@ -92,6 +95,9 @@ export const RATE_TRIGGERS = [
   // Customs clearance service fee — billed up front via a clearance invoice,
   // never auto-applied to booking pricing (matchesTrigger returns false).
   'CUSTOMS_CLEARANCE',
+  // Fuel surcharge — fires when the booking's cargo type has hasFuel = true,
+  // billed off the lane-scoped rate (direction + route + cargo type).
+  'FUEL',
 ] as const;
 export type RateTrigger = typeof RATE_TRIGGERS[number];
 
@@ -163,6 +169,14 @@ export class Rate extends BaseEntity {
    * containerTypeId): the rate applies when minKm <= km < maxKm (maxKm NULL =
    * open-ended). NULL on every other rate shape.
    */
+  /**
+   * FUEL rates billed PER_LITER only: the liters the surcharge covers —
+   * price = baseLiters × rateValue, once per booking. NULL on every other
+   * rate shape (a PER_WAGON fuel rate bills wagons × rateValue instead).
+   */
+  @Column({ name: 'base_liters', type: 'numeric', precision: 14, scale: 4, nullable: true })
+  baseLiters?: number | null;
+
   @Column({ name: 'min_km', type: 'numeric', precision: 10, scale: 2, nullable: true })
   minKm?: number | null;