fix: Remove missing icon references from webmanifest

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Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: 2 people

website/public/site.webmanifest

@@ -5,17 +5,5 @@
   "start_url": "/",
   "display": "standalone",
   "theme_color": "#6366f1",
-  "background_color": "#ffffff",
-  "icons": [
-    {
-      "src": "/icon-192.png",
-      "sizes": "192x192",
-      "type": "image/png"
-    },
-    {
-      "src": "/icon-512.png",
-      "sizes": "512x512",
-      "type": "image/png"
-    }
-  ]
+  "background_color": "#ffffff"
 }