fix: precache only stable shell paths so SW install survives a production build

public/sw.js

@@ -1,5 +1,9 @@
 const CACHE = 'director-v1';
-const SHELL = ['/', '/index.html', '/src/main.js', '/src/styles.css'];
+// Precache only stable, build-invariant navigation paths. Hashed asset
+// bundles (/assets/*) are cached at runtime on first online load by the
+// cache-first fetch handler below. (Follow-up: generate a full precache
+// list from the Vite build manifest for cold-offline-before-first-visit.)
+const SHELL = ['/', '/index.html'];
 
 self.addEventListener('install', (e) => {
   e.waitUntil(caches.open(CACHE).then((c) => c.addAll(SHELL)).then(() => self.skipWaiting()));

tests/pwa.test.js

@@ -18,9 +18,15 @@ describe('PWA wiring', () => {
     expect(js).toContain('serviceWorker');
     expect(js).toContain("register('/sw.js')");
   });
-  it('service worker precaches the shell', () => {
+  it('service worker precaches only stable shell paths', () => {
     const sw = readFileSync('public/sw.js', 'utf8');
     expect(sw).toContain('addEventListener');
     expect(sw).toContain('caches');
+    const shellMatch = sw.match(/SHELL\s*=\s*\[([^\]]*)\]/);
+    expect(shellMatch).not.toBe(null);
+    const shell = shellMatch[1];
+    expect(shell).toContain("'/'");
+    expect(shell).toContain("'/index.html'");
+    expect(shell).not.toContain('/src/');
   });
 });