fix(i18n): persist CMS translations and validate message catalogs

src/i18n/locales.ts

@@ -0,0 +1,32 @@
+export const SUPPORTED_LOCALES = [
+	"en",
+	"it",
+	"nl",
+	"de",
+	"fr",
+	"es",
+	"pt",
+	"pl",
+	"sv",
+	"tr",
+	"ro",
+	"hu",
+	"cs",
+	"sk",
+	"da",
+	"no",
+	"el",
+	"bg",
+	"hr",
+	"sr",
+	"uk",
+	"ru",
+] as const;
+export type AppLocale = (typeof SUPPORTED_LOCALES)[number];
+export const DEFAULT_LOCALE: AppLocale = "en";
+
+export function isSupportedLocale(
+	value: string | undefined,
+): value is AppLocale {
+	return !!value && (SUPPORTED_LOCALES as readonly string[]).includes(value);
+}