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/Admin/Support/ResolveTicketCommandHandlerTests.cs

@@ -68,14 +68,13 @@ public class ResolveTicketCommandHandlerTests
     }
 
     [Fact]
-    public async Task Handle_WhenRoleRequest_ReturnsOnlyBugReportCanBeResolvedDirectly()
+    public async Task Handle_WhenExtensionRequest_ReturnsOnlyBugReportCanBeResolvedDirectly()
     {
-        // Заявку на роль/продление можно решить только через Approve/Reject — Resolve обходил бы
-        // одобрение (роль/продление так и не назначились бы), см. CLAUDE.md.
+        // Заявку на продление можно решить только через Approve/Reject — Resolve обходил бы
+        // одобрение (дни так и не начислились бы), см. CLAUDE.md.
         using var dbContext = InMemoryDbContextFactory.Create();
         var userId = Guid.NewGuid();
-        var roleId = Guid.NewGuid();
-        var ticket = SupportTicket.CreateRoleRequestForExistingRole(userId, roleId);
+        var ticket = SupportTicket.CreateExtensionRequest(userId, 14);
         dbContext.SupportTickets.Add(ticket);
         await dbContext.SaveChangesAsync(CancellationToken.None);