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).

pnpm-workspace.yaml

@@ -0,0 +1,10 @@
+# https://pnpm.io/settings
+
+allowBuilds:
+  '@parcel/watcher': true
+  core-js: true
+  electron-winstaller: true
+  esbuild: true
+  lightningcss: true
+  rolldown: true
+  unrs-resolver: true