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/AuthErrors.cs

@@ -0,0 +1,29 @@
+using TeleWave.Application.Common.Models;
+
+namespace TeleWave.Application.Auth;
+
+public static class AuthErrors
+{
+    public static readonly Error InvalidCredentials =
+        Error.Unauthorized("Auth.InvalidCredentials", "Неверное имя пользователя или пароль.");
+
+    public static readonly Error Unauthorized = Error.Unauthorized(
+        "Auth.Unauthorized",
+        "Требуется вход в систему."
+    );
+
+    public static readonly Error InvalidRefreshToken = Error.Unauthorized(
+        "Auth.InvalidRefreshToken",
+        "Сессия истекла, войдите заново."
+    );
+
+    public static readonly Error Blocked = Error.Forbidden(
+        "Auth.Blocked",
+        "Аккаунт заблокирован администратором."
+    );
+
+    public static readonly Error UserNameTaken = Error.Conflict(
+        "Auth.UserNameTaken",
+        "Это имя пользователя уже занято."
+    );
+}