fix(cbe): update response code from 3 to 2 for business failures in CBE integration

apps/edr-payment-api/src/modules/cbe-bill/mappers/cbe-error.mapper.ts

@@ -16,8 +16,8 @@ export class CbeBillError extends Error {
 }
 
 /**
- * Every failure maps to Response_Code "3" — the AAFDA spec (§2.10, §3.10) defines only
- * 0 (success), 1 (auth), 3 (business); only the description is specific (plan §6.6).
+ * Every failure maps to Response_Code "2" (per current CBE integration requirement; the
+ * original AAFDA plan used 3); only the description is specific (plan §6.6).
  */
 export function toCbeFailure(err: unknown): {
   description: string;