fix: fallback warning

frontend/svelte.config.js

@@ -11,9 +11,7 @@ const config = {
 		// adapter-auto only supports some environments, see https://kit.svelte.dev/docs/adapter-auto for a list.
 		// If your environment is not supported or you settled on a specific environment, switch out the adapter.
 		// See https://kit.svelte.dev/docs/adapters for more information about adapters.
-		adapter: adapter({
-			fallback: 'index.html'
-		}),
+		adapter: adapter(),
 		prerender: {
 			entries: [
 				'/',