feat: creats frontend for the project

frontend/src/utils/format.ts

@@ -0,0 +1,38 @@
+const amountFormatter = new Intl.NumberFormat('ru-RU', {
+  style: 'currency',
+  currency: 'RUB',
+  minimumFractionDigits: 2,
+});
+
+export function formatAmount(kopecks: number): string {
+  return amountFormatter.format(kopecks / 100);
+}
+
+const dateFormatter = new Intl.DateTimeFormat('ru-RU', {
+  day: '2-digit',
+  month: '2-digit',
+  year: 'numeric',
+});
+
+const dateTimeFormatter = new Intl.DateTimeFormat('ru-RU', {
+  day: '2-digit',
+  month: '2-digit',
+  year: 'numeric',
+  hour: '2-digit',
+  minute: '2-digit',
+});
+
+export function formatDate(iso: string): string {
+  return dateFormatter.format(new Date(iso));
+}
+
+export function formatDateTime(iso: string): string {
+  return dateTimeFormatter.format(new Date(iso));
+}
+
+export function toISODate(date: Date): string {
+  const y = date.getFullYear();
+  const m = String(date.getMonth() + 1).padStart(2, '0');
+  const d = String(date.getDate()).padStart(2, '0');
+  return `${y}-${m}-${d}`;
+}