fix(vant-cli): pnpm compatibility (#10214)

* fix(vant-cli): pnpm compatibility

* chore: clean code, semantic naming

packages/vant-cli/src/compiler/gen-site-mobile-shared.ts

@@ -1,12 +1,11 @@
 import { join } from 'path';
 import { existsSync, readdirSync } from 'fs';
-import { SRC_DIR, SITE_MOBILE_SHARED_FILE } from '../common/constant.js';
+import { SRC_DIR } from '../common/constant.js';
 import {
   pascalize,
   removeExt,
   decamelize,
   getVantConfig,
-  smartOutputFile,
   normalizePath,
 } from '../common/index.js';
 import { CSS_LANG } from '../common/css.js';
@@ -68,7 +67,7 @@ function genCode(components: string[]) {
     }))
     .filter((item) => existsSync(item.path));
 
-  return `import './package-style.${CSS_LANG}';
+  return `import 'package-style.${CSS_LANG}';
 ${genImports(demos)}
 
 ${genExports(demos)}
@@ -80,5 +79,5 @@ export function genSiteMobileShared() {
   const dirs = readdirSync(SRC_DIR);
   const code = genCode(dirs);
 
-  smartOutputFile(SITE_MOBILE_SHARED_FILE, code);
+  return code;
 }