refactor: enforce enum machine codes

Use owner enums for error and T-Bank protocol values with ESLint regression checks.

Preserve open wire fallbacks and keep protocol imports independent of DI and Prisma.

Verified npm ci, verify, 226 unit tests, 262 isolated e2e tests and unchanged OpenAPI.

src/modules/investments/income/income-analytics.service.ts

@@ -8,6 +8,7 @@ import {
   formatDecimal,
   subtract,
 } from '../../../common/decimal';
+import { isTbankProtocolValue, TbankOperationType } from '../../../integrations/tbank/tbank-protocol';
 import { DateOnlyRange, moscowDate } from '../investment-calendar';
 import { investmentResourceMeta } from '../investment-resource.mapper';
 import {
@@ -165,7 +166,7 @@ function qualifying(entries: BrokerageOperationDto[]): BrokerageOperationDto[] {
   return entries.filter(
     (entry) =>
       Boolean(entry.payment) &&
-      ['OPERATION_TYPE_COUPON', 'OPERATION_TYPE_DIVIDEND'].includes(entry.type),
+      [TbankOperationType.Coupon, TbankOperationType.Dividend].some((type) => isTbankProtocolValue(entry.type, type)),
   );
 }
 
@@ -184,7 +185,7 @@ function totals(entries: BrokerageOperationDto[]): IncomeCurrencySummaryDto[] {
     if (!entry.payment) continue;
     const total = values.get(entry.payment.currency) ?? zeroTotal();
     const value = decimalFromString(entry.payment.value);
-    if (entry.type === 'OPERATION_TYPE_COUPON') {
+    if (isTbankProtocolValue(entry.type, TbankOperationType.Coupon)) {
       total.coupon = add(total.coupon, value);
     } else total.dividend = add(total.dividend, value);
     values.set(entry.payment.currency, total);

src/modules/investments/income/income-period.ts

@@ -8,6 +8,8 @@ import {
   utcDate,
 } from '../investment-calendar';
 
+enum IncomeErrorCode { InvalidPeriod = 'INVALID_INCOME_PERIOD' }
+
 const MONDAY_WEEKDAY_INDEX = 1;
 const INCLUSIVE_DAY_OFFSET = 1;
 const NEXT_DAY_OFFSET = 1;
@@ -163,5 +165,5 @@ function yearAgo(range: DateOnlyRange): DateOnlyRange | null {
 }
 
 function invalidPeriod(): BadRequestException {
-  return new BadRequestException({ code: 'INVALID_INCOME_PERIOD' });
+  return new BadRequestException({ code: IncomeErrorCode.InvalidPeriod });
 }