Fix persistent caching: no-store/no-cache headers, SW v4, versioned asset URLs

app/public/index.html

@@ -16,7 +16,7 @@
 <link rel="preconnect" href="https://fonts.googleapis.com">
 <link href="https://fonts.googleapis.com/css2?family=Manrope:wght@400;500;600;700&family=Playfair+Display:wght@500;600&display=swap" rel="stylesheet">
 <link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css">
-<link rel="stylesheet" href="style.css">
+<link rel="stylesheet" href="style.css?v=4">
 </head>
 <body>
 <div class="app">
@@ -301,7 +301,7 @@
 </div><!-- .app -->
 
 <script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js"></script>
-<script src="app.js"></script>
+<script src="app.js?v=4"></script>
 <script>
   if ('serviceWorker' in navigator) {
     window.addEventListener('load', () => {

app/public/sw.js

@@ -1,12 +1,12 @@
 'use strict';
 
-const CACHE = 'weather-v3';
+const CACHE = 'weather-v4';
 
 // App shell — cached on install for offline use
 const PRECACHE = [
   '/',
-  '/app.js',
-  '/style.css',
+  '/app.js?v=4',
+  '/style.css?v=4',
   '/manifest.json',
   '/icons/icon.svg'
 ];

app/server.js

@@ -105,6 +105,16 @@ function ensurePushConfigured() {
   return true;
 }
 
+// HTML: never cache (always revalidate so SW/app updates are picked up immediately)
+app.use('/', (req, res, next) => {
+  if (req.path === '/' || req.path.endsWith('.html')) {
+    res.setHeader('Cache-Control', 'no-store');
+  } else if (req.path.endsWith('.css') || req.path.endsWith('.js') || req.path === '/sw.js' || req.path === '/manifest.json') {
+    // Short-lived cache — browser revalidates every 60 s but still gets a 304 fast
+    res.setHeader('Cache-Control', 'no-cache');
+  }
+  next();
+});
 app.use(express.static(path.join(__dirname, 'public')));
 
 app.get('/healthz', (_req, res) => {