Set up initial frontend with Vite and integrated Docker for full-stack build

backend/public/sw.js

@@ -0,0 +1,23 @@
+const CACHE = "budget-commun-v2";
+const ASSETS = ["/", "/index.html", "/manifest.json"];
+
+self.addEventListener("install", e => {
+  e.waitUntil(caches.open(CACHE).then(c => c.addAll(ASSETS)));
+  self.skipWaiting();
+});
+
+self.addEventListener("activate", e => {
+  e.waitUntil(caches.keys().then(keys =>
+    Promise.all(keys.filter(k => k !== CACHE).map(k => caches.delete(k)))
+  ));
+  self.clients.claim();
+});
+
+self.addEventListener("fetch", e => {
+  // API calls: network only
+  if (e.request.url.includes("/api/")) return;
+  // Static: cache first
+  e.respondWith(
+    caches.match(e.request).then(cached => cached || fetch(e.request))
+  );
+});