Create nix derivations for building and running web app

web-app/svelte.config.js

@@ -0,0 +1,18 @@
+import adapter from "@sveltejs/adapter-node";
+import { vitePreprocess } from "@sveltejs/vite-plugin-svelte";
+
+/** @type {import('@sveltejs/kit').Config} */
+const config = {
+  // Consult https://kit.svelte.dev/docs/integrations#preprocessors
+  // for more information about preprocessors
+  preprocess: vitePreprocess(),
+
+  kit: {
+    // 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()
+  }
+};
+
+export default config;