fix: change SW cache mechanism

public/sw.js

@@ -1,8 +1,8 @@
 // Service Worker for Claude Code UI PWA
-const CACHE_NAME = 'claude-ui-v1';
+// Cache only manifest (needed for PWA install). HTML and JS are never pre-cached
+// so a rebuild + refresh always picks up the latest assets.
+const CACHE_NAME = 'claude-ui-v2';
 const urlsToCache = [
-  '/',
-  '/index.html',
   '/manifest.json'
 ];
 
@@ -10,44 +10,63 @@ const urlsToCache = [
 self.addEventListener('install', event => {
   event.waitUntil(
     caches.open(CACHE_NAME)
-      .then(cache => {
-        return cache.addAll(urlsToCache);
-      })
+      .then(cache => cache.addAll(urlsToCache))
   );
   self.skipWaiting();
 });
 
-// Fetch event
+// Fetch event — network-first for everything except hashed assets
 self.addEventListener('fetch', event => {
-  // Never cache API requests or WebSocket upgrades
-  if (event.request.url.includes('/api/') || event.request.url.includes('/ws')) {
+  const url = event.request.url;
+
+  // Never intercept API requests or WebSocket upgrades
+  if (url.includes('/api/') || url.includes('/ws')) {
     return;
   }
 
-  event.respondWith(
-    caches.match(event.request)
-      .then(response => {
-        if (response) {
+  // Navigation requests (HTML) — always go to network, no caching
+  if (event.request.mode === 'navigate') {
+    event.respondWith(
+      fetch(event.request).catch(() => caches.match('/manifest.json').then(() =>
+        new Response('<h1>Offline</h1><p>Please check your connection.</p>', {
+          headers: { 'Content-Type': 'text/html' }
+        })
+      ))
+    );
+    return;
+  }
+
+  // Hashed assets (JS/CSS in /assets/) — cache-first since filenames change per build
+  if (url.includes('/assets/')) {
+    event.respondWith(
+      caches.match(event.request).then(cached => {
+        if (cached) return cached;
+        return fetch(event.request).then(response => {
+          const clone = response.clone();
+          caches.open(CACHE_NAME).then(cache => cache.put(event.request, clone));
           return response;
-        }
-        return fetch(event.request);
-      }
-    )
+        });
+      })
+    );
+    return;
+  }
+
+  // Everything else — network-first
+  event.respondWith(
+    fetch(event.request).catch(() => caches.match(event.request))
   );
 });
 
-// Activate event
+// Activate event — purge old caches
 self.addEventListener('activate', event => {
   event.waitUntil(
-    caches.keys().then(cacheNames => {
-      return Promise.all(
-        cacheNames.map(cacheName => {
-          if (cacheName !== CACHE_NAME) {
-            return caches.delete(cacheName);
-          }
-        })
-      );
-    })
+    caches.keys().then(cacheNames =>
+      Promise.all(
+        cacheNames
+          .filter(name => name !== CACHE_NAME)
+          .map(name => caches.delete(name))
+      )
+    )
   );
   self.clients.claim();
 });