Add subscription info refresh endpoint and UI stats

src/web/utils/clientControls.js

@@ -34,3 +34,31 @@ export function localProxyUrls(port = 8082) {
     http: `http://127.0.0.1:${port}`,
   };
 }
+
+export function subscriptionUsage(userInfo = {}) {
+  const upload = Math.max(0, Number(userInfo.upload) || 0);
+  const download = Math.max(0, Number(userInfo.download) || 0);
+  const total = Math.max(0, Number(userInfo.total) || 0);
+  const used = upload + download;
+
+  return {
+    upload,
+    download,
+    total,
+    used,
+    percent: total ? Math.min(100, (used / total) * 100) : null,
+    expiresAt: userInfo.expire ? new Date(Number(userInfo.expire) * 1000) : null,
+  };
+}
+
+export function subscriptionDaysLeft(expiresAt, now = Date.now()) {
+  const days = Math.ceil((expiresAt?.getTime() - now) / 86_400_000);
+  if (!Number.isFinite(days)) return '';
+  if (days <= 0) return 'срок истёк';
+  const mod10 = days % 10;
+  const mod100 = days % 100;
+  const unit = mod10 === 1 && mod100 !== 11
+    ? 'день'
+    : mod10 >= 2 && mod10 <= 4 && (mod100 < 12 || mod100 > 14) ? 'дня' : 'дней';
+  return `${days === 1 ? 'остался' : 'осталось'} ${days} ${unit}`;
+}