fix admin save state architecture

app/root/smtp/actions.ts

@@ -5,6 +5,7 @@ import { redirect } from "next/navigation";
 import { isRedirectError } from "next/dist/client/components/redirect";
 
 import { clearAdminSessionCookie, isAdminAuthenticated } from "@/lib/admin-auth";
+import { isCheckedFormValue } from "@/lib/form-data";
 import {
   getMailSettings,
   updateMailSettings,
@@ -53,7 +54,7 @@ function parseMailSettingsFormData(
     smtp: {
       host,
       port: parsePort(portValue || String(existingSettings.smtp.port)),
-      secure: formData.get("smtpSecure") === "on",
+      secure: isCheckedFormValue(formData.get("smtpSecure")),
       username,
       password: password.trim() ? password : existingSettings.smtp.password,
     },