feat: Implement AuthService for user registration with detailed field error handling and updated user roles.

src/services/index.ts

@@ -0,0 +1,16 @@
+// API Client
+export { default as api } from './api';
+export type { ApiResponse, ApiErrorResponse } from './api';
+
+// Services
+export { authService, AuthService } from './auth.service';
+export type {
+  RegisterRequest,
+  LoginRequest,
+  AuthUser,
+  AuthResponse,
+  ForgotPasswordRequest,
+  ResetPasswordRequest,
+  VerifyEmailRequest,
+  MessageResponse,
+} from './auth.service';