fix: image backgrounds not working after build

vite.config.ts

@@ -29,7 +29,8 @@ export default defineConfig({
     minify: false,
     rollupOptions: {
       input: {
-        settings: join(__dirname, 'src', 'interface', 'index.html')
+        settings: join(__dirname, 'src', 'interface', 'index.html'),
+        backgrounds: join(__dirname, 'src', 'seqta', 'ui', 'background', 'background.html')
       }
     }
   }