fix: update stale comment and remove extra blank line

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: bartlomieju

packages/plugin-vite/src/plugins/patches/commonjs.ts

@@ -364,9 +364,8 @@ export function cjsPlugin(
               const mapped = mappedNs[i];
 
               const key = path.scope.generateUid("k");
-              // Guard the for-in body with a typeof check so that
-              // namespace properties are not assigned onto a primitive
-              // default (e.g. when exports.default is a string).
+              // Only spread namespace properties when the module has no
+              // explicit default export (i.e. "default" not in exports).
               path.pushContainer(
                 "body",
                 t.ifStatement(

packages/plugin-vite/src/plugins/patches/commonjs_test.ts

@@ -36,7 +36,6 @@ if (typeof exports === "object" && exports !== null && "default" in exports) {
   _default = exports;
 }`;
 
-
 const DEFAULT_EXPORT_END = `export default _default;
 export var __require = exports;`;
 const IMPORT_REQUIRE = `import { createRequire } from "node:module";