Web app manifest and icons (#50)

Co-authored-by: dev_agent <dev_agent@cubecraftlabs.com>
Co-committed-by: dev_agent <dev_agent@cubecraftlabs.com>

web/src/sw.ts

@@ -0,0 +1,17 @@
+// MealQuest service worker. vite-plugin-pwa replaces self.__WB_MANIFEST with
+// the build's precache list, and installing caches every entry. Serving from
+// that cache, expiring old entries and the update flow belong to the runtime
+// caching strategies, which are not built yet.
+
+export {}
+
+declare const self: ServiceWorkerGlobalScope & {
+  __WB_MANIFEST: Array<{ url: string; revision: string | null }>
+}
+
+const precacheName = 'mealquest-precache'
+const precacheURLs = self.__WB_MANIFEST.map((entry) => entry.url)
+
+self.addEventListener('install', (event) => {
+  event.waitUntil(caches.open(precacheName).then((cache) => cache.addAll(precacheURLs)))
+})