fix(tochka): allow saving credential with empty customerCode/accountCode

User flow: paste JWT -> save -> «Проверить» fetches customers list ->
fill customerCode/accountId from that list. Required min(1) blocked this.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/api/src/modules/tochka/routes.ts

@@ -10,7 +10,9 @@ const ENV = ['sandbox', 'prod'] as const;
 const CredentialUpsert = z.object({
   environment: z.enum(ENV),
   jwt: z.string().min(5),
-  customerCode: z.string().min(1).max(100),
+  // customerCode/accountCode можно оставить пустыми и заполнить после «Проверить»:
+  // тестовый запрос к /open-banking/v1.0/customers вернёт реальные коды.
+  customerCode: z.preprocess((v) => (typeof v === 'string' ? v.trim() : v), z.string().max(100).default('')),
   accountCode: optionalText(100),
   bankAccountId: z.string().uuid().nullable(),
 });