Fix flake to build with vite

flake.nix

@@ -32,6 +32,7 @@
         buildInputs = with pkgs; [
           openssl
           sqlite
+          nodejs_20
         ];
       in {
         devShells.default = pkgs.mkShell {
@@ -53,10 +54,17 @@
 
           inherit nativeBuildInputs buildInputs;
 
-          # Copy static files to the output
+          # Build the Vite assets and copy them to the output
+          preInstall = ''
+            cd static
+            npm install
+            npm run build
+            cd ..
+          '';
+
           postInstall = ''
             mkdir -p $out
-            cp -r static $out
+            cp -r static/dist $out/static
             cp -r templates $out
           '';