feat: show VPN connection info and subscription request history on admin user detail

- Load panelInfo eagerly on page load (not just on subscription tab)
- Add VPN connection card to info tab: last/first connection, online status indicator, last node
- Rename "Last activity" to "Bot activity" to distinguish from VPN connection
- Show cabinet_last_login field that was never rendered
- Add collapsible subscription request history section in subscription tab with paginated table
- Add subscription request history API types and method
- Add i18n keys for all 4 locales (ru, en, zh, fa)

src/api/adminUsers.ts

@@ -158,6 +158,19 @@ export interface UserPanelInfo {
   last_connected_node_name: string | null;
 }
 
+export interface SubscriptionRequestRecord {
+  id: number;
+  userUuid: string;
+  requestAt: string;
+  requestIp: string | null;
+  userAgent: string | null;
+}
+
+export interface SubscriptionRequestHistory {
+  total: number;
+  records: SubscriptionRequestRecord[];
+}
+
 export interface UserNodeUsageItem {
   node_uuid: string;
   node_name: string;
@@ -684,6 +697,22 @@ export const adminUsersApi = {
     return response.data;
   },
 
+  // Get subscription request history from RemnaWave panel
+  getSubscriptionRequestHistory: async (
+    userId: number,
+    subscriptionId?: number,
+    offset = 0,
+    limit = 20,
+  ): Promise<SubscriptionRequestHistory> => {
+    const params: Record<string, unknown> = { offset, limit };
+    if (subscriptionId != null) params.subscription_id = subscriptionId;
+    const response = await apiClient.get(
+      `/cabinet/admin/users/${userId}/subscription-request-history`,
+      { params },
+    );
+    return response.data;
+  },
+
   // Get user devices
   getUserDevices: async (
     userId: number,