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/Auth/ChangePassword/ChangePasswordCommand.cs

@@ -0,0 +1,6 @@
+using LiteCqrs;
+using TeleWave.Application.Common.Models;
+
+namespace TeleWave.Application.Auth.ChangePassword;
+
+public sealed record ChangePasswordCommand(string CurrentPassword, string NewPassword) : ICommand<Result>;

backend/src/TeleWave.Application/Auth/ChangePassword/ChangePasswordCommandHandler.cs

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+using LiteCqrs;
+using TeleWave.Application.Common.Interfaces;
+using TeleWave.Application.Common.Models;
+
+namespace TeleWave.Application.Auth.ChangePassword;
+
+public sealed class ChangePasswordCommandHandler(
+    IIdentityService identityService,
+    ICurrentUser currentUser
+) : ICommandHandler<ChangePasswordCommand, Result>
+{
+    public async Task<Result> Handle(
+        ChangePasswordCommand command,
+        CancellationToken cancellationToken
+    )
+    {
+        if (currentUser.UserId is not { } userId)
+            return Result.Failure(AuthErrors.Unauthorized);
+
+        return await identityService.ChangePasswordAsync(
+            userId,
+            command.CurrentPassword,
+            command.NewPassword,
+            cancellationToken
+        );
+    }
+}

backend/src/TeleWave.Application/Auth/ChangePassword/ChangePasswordCommandValidator.cs

@@ -0,0 +1,12 @@
+using FluentValidation;
+
+namespace TeleWave.Application.Auth.ChangePassword;
+
+public sealed class ChangePasswordCommandValidator : AbstractValidator<ChangePasswordCommand>
+{
+    public ChangePasswordCommandValidator()
+    {
+        RuleFor(x => x.CurrentPassword).NotEmpty();
+        RuleFor(x => x.NewPassword).NotEmpty().MinimumLength(8);
+    }
+}