Don't create separate assets package

flake.nix

@@ -33,23 +33,6 @@
             pname = "entrance-exam";
             version = "0.1.0";
 
-            buildPhase = ''
-              # Compile bootsnap cache
-              ${gems}/bin/bundle exec bootsnap precompile --gemfile app/ lib/
-            '';
-
-            installPhase = ''
-              mkdir $out
-              cp -r * $out
-              rm -r $out/public
-            '';
-
-            passthru = {
-              assets = pkgs.stdenv.mkDerivation {
-                inherit src version;
-
-                pname = "entrance-exam-assets";
-
             nativeBuildInputs = with pkgs; [
               nodejs
               yarnConfigHook
@@ -62,15 +45,17 @@
             };
 
             buildPhase = ''
+              # Compile bootsnap cache
+              ${gems}/bin/bundle exec bootsnap precompile --gemfile app/ lib/
               SECRET_KEY_BASE=000000 RAILS_ENV=production SKIP_YARN_INSTALL=1 ${gems}/bin/bundle exec rails assets:precompile
             '';
 
             installPhase = ''
-                  cp -r public $out
+              mkdir $out
+              cp -r * $out
             '';
-              };
-              env = gems;
-            };
+
+            passthru.env = gems;
           };
         };