fix: align SubscriptionRequestRecord type with Remnawave 2.8.0

The panel renamed the subscription-request-history field userUuid (uuid)
-> userId (number) in 2.8.0. The field is never read in the UI (render
uses id/requestAt/requestIp/userAgent), so this is a type-accuracy fix
only. tsc --noEmit passes.

src/api/adminUsers.ts

@@ -161,7 +161,8 @@ export interface UserPanelInfo {
 
 export interface SubscriptionRequestRecord {
   id: number;
-  userUuid: string;
+  // Remnawave 2.8.0 renamed this panel field userUuid (uuid) -> userId (number).
+  userId: number;
   requestAt: string;
   requestIp: string | null;
   userAgent: string | null;