Wire SW update prompt and request persistent storage (M6, web.dev)

src/main.tsx

@@ -4,6 +4,7 @@ import { initPanes, wirePanes } from './app/orchestration/panes';
 import { initPreviewFitMode, wirePreviewFitMode } from './app/orchestration/preferences';
 import { initSettings, wireSettings } from './app/orchestration/settings';
 import { initSnippetSort, wireSnippetSort } from './app/orchestration/snippet-sort';
+import { initPersistentStorage, registerServiceWorker } from './app/orchestration/pwa';
 import { initApp } from './app/orchestration/startup';
 import { initTheme, wireTheme } from './app/orchestration/theme';
 import '../styles/base.css';
@@ -37,4 +38,9 @@ wireSettings();
 // hydration resolves.
 void initApp();
 
+// PWA: register the service worker (prompt the user to reload on an update) and
+// request persistent storage so the local-first workspace isn't evicted (web.dev).
+registerServiceWorker();
+initPersistentStorage();
+
 createRoot(document.getElementById('app')!).render(<App />);