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).

.gitignore

@@ -0,0 +1,26 @@
+.DS_Store
+.thumbs.db
+node_modules
+
+# .env files
+.env*
+
+# Quasar core related directories
+.quasar
+/dist
+/quasar.config.*.temporary.compiled*
+
+# Cordova related directories and files
+/src-cordova/node_modules
+/src-cordova/platforms
+/src-cordova/plugins
+/src-cordova/www
+
+# Capacitor related directories and files
+/src-capacitor/www
+/src-capacitor/node_modules
+
+# Log files
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*