add auth

internal/auth/domain/errors.go

@@ -0,0 +1,11 @@
+package domain
+
+import "errors"
+
+var (
+	ErrUserNotFound      = errors.New("user not found")
+	ErrInvalidEmail      = errors.New("invalid email")
+	ErrInvalidPassword   = errors.New("invalid password")
+	ErrUserAlreadyExists = errors.New("user already exists")
+	ErrInvalidToken      = errors.New("invalid token")
+)