Enhance user plan management and update related endpoints

- Added new configuration options for user plans in `.env.example`, including `Plans__MaxCustomConfigCount` and `Plans__MinCustomConfigCount`.
- Introduced `MapPlanEndpoints` in `Program.cs` to handle plan-related API routes.
- Implemented `SetUserPlan` endpoint in `RoleEndpoints` to allow admins to assign plans to users.
- Removed deprecated role request approval endpoints from `AdminSupportEndpoints`.
- Updated `ITelegramNotifier` and related classes to reflect changes in role request handling and payment notifications.
- Refactored role management commands to remove `MaxConfigs` and focus on `MaxIpLimit` and billing settings.
- Enhanced billing request handling to accommodate plan changes instead of role changes.
- Updated various interfaces and command handlers to support new plan management features.

backend/tests/PnvPanel.Application.Tests/Support/ReopenTicketCommandHandlerTests.cs

@@ -85,13 +85,13 @@ public class ReopenTicketCommandHandlerTests
     }
 
     [Fact]
-    public async Task Handle_WhenRoleRequestResolved_ReturnsOnlyBugReportCanBeReopened()
+    public async Task Handle_WhenExtensionRequestResolved_ReturnsOnlyBugReportCanBeReopened()
     {
-        // approve/reject — единственный способ решить заявку на роль/продление (см. CLAUDE.md);
-        // Reopen для них запрещён даже если тикет каким-то образом оказался Resolved.
+        // approve/reject — единственный способ решить заявку на продление (см. CLAUDE.md);
+        // Reopen для неё запрещён даже если тикет каким-то образом оказался Resolved.
         using var dbContext = InMemoryDbContextFactory.Create();
         var userId = Guid.NewGuid();
-        var ticket = SupportTicket.CreateRoleRequestForExistingRole(userId, Guid.NewGuid());
+        var ticket = SupportTicket.CreateExtensionRequest(userId, 14);
         ticket.Resolve();
         dbContext.SupportTickets.Add(ticket);
         await dbContext.SaveChangesAsync(CancellationToken.None);