refactor: centralize domain values and enforce numeric lint

src/modules/banking/bank-cards/domain/bank-card.calculations.ts

@@ -1,3 +1,6 @@
+import { BankOperationKind } from './bank-operation-kind';
+
+const ISO_MONTH_LENGTH = 7;
 export function moscowToday(now = new Date()): string {
   return new Intl.DateTimeFormat('en-CA', {
     timeZone: 'Europe/Moscow',
@@ -30,12 +33,21 @@ export function bankBalance(
   let balance = opening;
   for (const operation of operations) {
     if (operation.cardId === cardId) {
-      if (operation.kind === 'expense' || operation.kind === 'transfer')
+      if (
+        operation.kind === BankOperationKind.Expense ||
+        operation.kind === BankOperationKind.Transfer
+      )
         balance -= operation.amountKopecks;
-      else if (operation.kind === 'topup' || operation.kind === 'refund')
+      else if (
+        operation.kind === BankOperationKind.Topup ||
+        operation.kind === BankOperationKind.Refund
+      )
         balance += operation.amountKopecks;
     }
-    if (operation.kind === 'transfer' && operation.targetCardId === cardId)
+    if (
+      operation.kind === BankOperationKind.Transfer &&
+      operation.targetCardId === cardId
+    )
       balance += operation.amountKopecks;
   }
   return balance;
@@ -60,13 +72,23 @@ export function bankSummary(
   for (const operation of operations) {
     if (
       typeof period === 'string'
-        ? operation.date.slice(0, 7) !== period
+        ? operation.date.slice(0, ISO_MONTH_LENGTH) !== period
         : operation.date < period.from || operation.date > period.to
     )
       continue;
-    if (operation.kind !== 'expense' && operation.kind !== 'refund') continue;
-    const expense = operation.kind === 'expense' ? operation.amountKopecks : 0n;
-    const refund = operation.kind === 'refund' ? operation.amountKopecks : 0n;
+    if (
+      operation.kind !== BankOperationKind.Expense &&
+      operation.kind !== BankOperationKind.Refund
+    )
+      continue;
+    const expense =
+      operation.kind === BankOperationKind.Expense
+        ? operation.amountKopecks
+        : 0n;
+    const refund =
+      operation.kind === BankOperationKind.Refund
+        ? operation.amountKopecks
+        : 0n;
     expenses += expense;
     refunds += refund;
     if (operation.categoryId !== null) {