Add CYD browser flasher with Next.js, i18n, and Web Serial install.

Replace the starter app with a public/local flasher that discovers sibling firmwares, supports en/zh, and documents HTTPS deploy.

Co-authored-by: Cursor <cursoragent@cursor.com>

i18n/routing.ts

@@ -0,0 +1,9 @@
+import { defineRouting } from "next-intl/routing";
+
+export const routing = defineRouting({
+  locales: ["en", "zh"],
+  defaultLocale: "en",
+  localePrefix: "always",
+});
+
+export type AppLocale = (typeof routing.locales)[number];