Initial commit: base slice (auth, roles, users, admin) scaffold

Backend: .NET 10 Clean Architecture + LiteCqrs.Net + EF Core/PostgreSQL +
Identity/JWT. Frontend: React 19 + Vite + TanStack Query/Router + Tailwind v4
with a retro CRT theme. Docker/compose deployment mirroring PnvPanel's
conventions, scoped down to the current base feature set.

backend/src/TeleWave.Application/Admin/Roles/CreateRole/CreateRoleCommandHandler.cs

@@ -0,0 +1,14 @@
+using LiteCqrs;
+using TeleWave.Application.Common.Interfaces;
+using TeleWave.Application.Common.Models;
+
+namespace TeleWave.Application.Admin.Roles.CreateRole;
+
+public sealed class CreateRoleCommandHandler(IRoleService roleService)
+    : ICommandHandler<CreateRoleCommand, Result<RoleDto>>
+{
+    public Task<Result<RoleDto>> Handle(
+        CreateRoleCommand command,
+        CancellationToken cancellationToken
+    ) => roleService.CreateRoleAsync(command.Name, cancellationToken);
+}