feat: Add PWA support with service worker and caching

- Implemented service worker registration in main.js
- Added icons for PWA in manifest.json
- Created a basic service worker (sw.js) for caching static assets
- Generated a list of files to cache using a Node.js script (generate-pwa-cache-list.js)
- Added icon images (icon-192.png and icon-512.png) for PWA
- Defined PWA manifest with app details and icon references

public/manifest.json

@@ -0,0 +1,20 @@
+{
+  "name": "Logo Gallery",
+  "description": "A collection of company and brand logos accessible via GitHub Pages",
+  "start_url": ".",
+  "display": "standalone",
+  "background_color": "#ffffff",
+  "theme_color": "#ffffff",
+  "icons": [
+    {
+      "src": "/icon-192.png",
+      "sizes": "192x192",
+      "type": "image/png"
+    },
+    {
+      "src": "/icon-512.png",
+      "sizes": "512x512",
+      "type": "image/png"
+    }
+  ]
+}