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-pwa/sw/custom-sw.ts

@@ -0,0 +1,39 @@
+/*
+ * This file (which will be your service worker)
+ * is picked up by the build system ONLY if
+ * quasar.config file > pwa > workboxMode is set to "InjectManifest"
+ */
+
+import { clientsClaim } from "workbox-core";
+import { NavigationRoute, registerRoute } from "workbox-routing";
+import {
+  cleanupOutdatedCaches,
+  createHandlerBoundToURL,
+  precacheAndRoute
+} from "workbox-precaching";
+
+declare const self: ServiceWorkerGlobalScope & typeof globalThis;
+
+void self.skipWaiting();
+clientsClaim();
+
+// Use with precache injection
+precacheAndRoute(self.__WB_MANIFEST);
+
+cleanupOutdatedCaches();
+
+if (import.meta.env.QUASAR_PROD) {
+  // Non-SSR/SSG fallbacks to index.html
+  // Production SSR/SSG fallbacks to offline.html (except for dev)
+  registerRoute(
+    new NavigationRoute(
+      createHandlerBoundToURL(import.meta.env.QUASAR_PWA_FALLBACK_HTML),
+      {
+        denylist: [
+          new RegExp(import.meta.env.QUASAR_PWA_SERVICE_WORKER_REGEX),
+          /workbox-(.)*\.js$/
+        ]
+      }
+    )
+  );
+}