update api

lib/core/errors/exceptions.dart

@@ -28,3 +28,23 @@ class UnauthorizedException implements Exception {
   final String message;
   UnauthorizedException([this.message = 'Unauthorized access']);
 }
+
+class AuthenticationException implements Exception {
+  final String message;
+  AuthenticationException([this.message = 'Authentication failed']);
+}
+
+class InvalidCredentialsException implements Exception {
+  final String message;
+  InvalidCredentialsException([this.message = 'Invalid email or password']);
+}
+
+class TokenExpiredException implements Exception {
+  final String message;
+  TokenExpiredException([this.message = 'Token has expired']);
+}
+
+class ConflictException implements Exception {
+  final String message;
+  ConflictException([this.message = 'Resource already exists']);
+}