chore: install cssbundling rails and set up compilation

spec/dummy/node_modules/sass/sass.js

@@ -0,0 +1,16 @@
+#!/usr/bin/env node
+
+require('./sass.dart.js');
+var library = globalThis._cliPkgExports.pop();
+if (globalThis._cliPkgExports.length === 0) delete globalThis._cliPkgExports;
+
+library.load({
+  readline: require("readline"),
+  chokidar: require("chokidar"),
+  util: require("util"),
+  stream: require("stream"),
+  fs: require("fs"),
+  immutable: require("immutable"),
+});
+
+library.cli_pkg_main_0_(process.argv.slice(2));