feat: add modular i18n foundation

src/i18n/types.ts

@@ -0,0 +1,9 @@
+export const supportedLocales = ["zh-CN", "en-US", "th-TH"] as const;
+
+export type SupportedLocale = (typeof supportedLocales)[number];
+
+export const defaultLocale: SupportedLocale = "zh-CN";
+
+export type LocaleMessageSchema<T> = {
+  readonly [Key in keyof T]: T[Key] extends string ? string : LocaleMessageSchema<T[Key]>;
+};