test: add domain LoginType constants test

Add test for LoginType enum constants:
- LoginTypePassword (1)
- LoginTypeEmailCode (2)
- LoginTypeSMSCode (3)
- LoginTypeOAuth (4)

internal/domain/model_test.go

@@ -0,0 +1,26 @@
+package domain
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLoginTypeConstants(t *testing.T) {
+	tests := []struct {
+		loginType LoginType
+		expected  int
+		name      string
+	}{
+		{LoginTypePassword, 1, "Password"},
+		{LoginTypeEmailCode, 2, "EmailCode"},
+		{LoginTypeSMSCode, 3, "SMSCode"},
+		{LoginTypeOAuth, 4, "OAuth"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expected, int(tt.loginType))
+		})
+	}
+}