sattle: Quasar PWA scaffold with lnurlcash-kit protocol core

M1: Quasar 2 / Vue 3 / TS / Pinia / i18n / PWA app shell in the lnurl-wallet
palette (#002222/#004444/#55ffcc, Noto Sans). Protocol layer is the external
lnurlcash-kit library (git dependency on the fork until upstream merges the
prepare fix / publishes to npm); keys.ts + receive.ts vendored from
lnurl-wallet with the derivation domain renamed to 'sattle'. Nix dev shell,
ci workflow (typecheck, vitest, pwa build).

src/boot/i18n.ts

@@ -0,0 +1,33 @@
+import { defineBoot } from '#q-app';
+import { createI18n } from 'vue-i18n';
+
+import messages from '@/i18n';
+
+export type MessageLanguages = keyof typeof messages;
+// Type-define 'en-US' as the master schema for the resource
+export type MessageSchema = (typeof messages)['en-US'];
+
+// See https://vue-i18n.intlify.dev/guide/advanced/typescript.html#global-resource-schema-type-definition
+/* eslint-disable @typescript-eslint/no-empty-object-type */
+declare module 'vue-i18n' {
+  // define the locale messages schema
+  export interface DefineLocaleMessage extends MessageSchema {}
+
+  // define the datetime format schema
+  export interface DefineDateTimeFormat {}
+
+  // define the number format schema
+  export interface DefineNumberFormat {}
+}
+/* eslint-enable @typescript-eslint/no-empty-object-type */
+
+export default defineBoot(({ app }) => {
+  const i18n = createI18n<{ message: MessageSchema }, MessageLanguages>({
+    locale: 'en-US',
+    legacy: false,
+    messages,
+  });
+
+  // Set i18n instance on app
+  app.use(i18n);
+});