feat(freight-api): add DJF as a supported currency

Adds DJF to freight.payments_currency_enum (migration 3860000000000,
alone in its own migration per Postgres's ADD VALUE-in-a-transaction
restriction) and to manual_payment_settings (djf_enabled column,
migration 3870000000000, default true).

Replaces the binary ETB/USD assumptions that would have silently
mispriced or discarded a DJF booking:
- booking-pricing / contract-pricing: usdToEtb scalar -> a rate table
  keyed by source currency (ExchangeService.getRateTable), so a
  contract-frozen rate converts into whatever currency the booking is
  paid in instead of being dropped when neither leg is ETB or USD.
- warehouse-fee / booking-wagon-cancellation: normalizeCurrency no
  longer coerces anything non-ETB to USD.
- additional-charge: convertAmount no longer bails out for a currency
  that isn't literally ETB or USD.
- manual-payment-settings: isEnabled/enabledCurrencies cover DJF.

Widens the three @IsIn(['ETB','USD']) DTO validators, and adds DJF to
the export/report currency filter option lists.

Claude-Session: https://claude.ai/code/session_01CZy77vCWhka3pnmVF9NDkL

apps/edr-freight-api/src/modules/warehouses/warehouse-fee.service.ts

@@ -1,6 +1,6 @@
 import { BadRequestException, Injectable, Logger, NotFoundException } from '@nestjs/common';
 import { Cron, CronExpression } from '@nestjs/schedule';
-import { ExchangeService } from '@edr/api-common';
+import { CURRENCY_CODES, CurrencyCode, ExchangeService } from '@edr/api-common';
 import { NotificationAudience, NotificationType } from '@edr/types';
 import { DataSource } from 'typeorm';
 
@@ -430,8 +430,11 @@ export class WarehouseFeeService {
     };
   }
 
-  private normalizeCurrency(currency?: string | null): 'ETB' | 'USD' {
-    return currency === 'ETB' ? 'ETB' : 'USD';
+  private normalizeCurrency(currency?: string | null): CurrencyCode {
+    const code = currency?.toUpperCase();
+    return (CURRENCY_CODES as readonly string[]).includes(code ?? '')
+      ? (code as CurrencyCode)
+      : 'USD';
   }
 
   private async convertAmount(amount: number, fromCurrency: string, toCurrency: string): Promise<number> {