Enhance user management and billing integration

- Updated the `UserSummaryDto` to include `BillingEnabled` and `BillingPaidUntil` properties, allowing for better tracking of user billing status.
- Refactored the `IdentityService` to populate the new billing fields when retrieving user summaries.
- Modified the dashboard and admin user management components to display billing information, including a link to the billing page and a badge for billing status.
- Added internationalization support for new billing-related labels in both English and Russian.
- Ensured frontend components reflect the updated user data structure, enhancing user experience with billing visibility.

backend/src/PnvPanel.Application/Common/Interfaces/IIdentityService.cs

@@ -34,7 +34,9 @@ public sealed record UserSummaryDto(
     string Role,
     bool IsActivated,
     bool IsBlocked,
-    DateTimeOffset? ActivatedAt
+    DateTimeOffset? ActivatedAt,
+    bool BillingEnabled,
+    DateTimeOffset? BillingPaidUntil
 );
 
 public sealed record UserStatsDto(int Total, int Activated);