refactor: update remnawave API types for v2.7.0

- ServerInfo: remove cpu_physical_cores, memory_available
- NodeInfo: replace cpu_count/cpu_model/total_ram with versions/system,
  xray_uptime changed to number, users_online now required
- NodeStatus: same field updates, remove dead uptime field
- Extract formatUptime to shared utils/format.ts
- Update AdminRemnawave and AdminDashboard components

src/utils/format.ts

@@ -1,3 +1,12 @@
+export function formatUptime(seconds: number): string {
+  const days = Math.floor(seconds / 86400);
+  const hours = Math.floor((seconds % 86400) / 3600);
+  const minutes = Math.floor((seconds % 3600) / 60);
+  if (days > 0) return `${days}d ${hours}h`;
+  if (hours > 0) return `${hours}h ${minutes}m`;
+  return `${minutes}m`;
+}
+
 export function formatPrice(kopeks: number): string {
   const rubles = kopeks / 100;
   return new Intl.NumberFormat('ru-RU', {