endpoint to update JWT cookies

app/delivery/web/api/public/auth.go

@@ -408,9 +408,12 @@ func (h *AuthHandler) GoogleCallback(c fiber.Ctx) error {
 
 	// Redirect to the locale-prefixed charts page after successful Google login.
 	// The user's preferred language is stored in the auth response; fall back to "en".
-	lang := response.User.Lang
-	if lang == "" {
-		lang = "en"
+	lang, err := h.authService.GetLangISOCode(response.User.LangID)
+	if err != nil {
+		return c.Status(responseErrors.GetErrorStatus(responseErrors.ErrBadLangID)).JSON(fiber.Map{
+			"error": responseErrors.GetErrorCode(c, responseErrors.ErrBadLangID),
+		})
 	}
+
 	return c.Redirect().To(h.config.App.BaseURL + "/" + lang)
 }