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).

README.md

@@ -0,0 +1,38 @@
+# sattle (sattle)
+
+## Install the dependencies
+
+```bash
+pnpm install
+# or: yarn/npm/bun install
+```
+
+### Start the app in development mode (HMR, error reporting, etc.)
+
+```bash
+quasar dev
+```
+
+### Format & Lint the files
+
+```bash
+pnpm run lint
+# or: yarn/npm/bun run lint
+```
+
+...or just check formatting & linting:
+
+```bash
+pnpm run lint:check
+# or: yarn/npm/bun run lint:check
+```
+
+### Build the app for production
+
+```bash
+quasar build
+```
+
+### Customize the configuration
+
+See [Configuring quasar.config.js](https://v2.quasar.dev/quasar-cli-vite/quasar-config-file).