fix: copy package.json to install dest for npm install

install.mjs

@@ -161,8 +161,9 @@ async function install() {
   if (existsSync(destDir)) rmSync(destDir, { recursive: true, force: true });
   copyDir(SRC_DIST_DIR, destDir);
 
-  // Copy openclaw.plugin.json
+  // Copy openclaw.plugin.json and package.json
   copyFileSync(join(__dirname, 'plugin', 'openclaw.plugin.json'), join(destDir, 'openclaw.plugin.json'));
+  copyFileSync(join(__dirname, 'plugin', 'package.json'), join(destDir, 'package.json'));
   logOk(`Plugin files → ${destDir}`);
 
   // Install runtime deps into dest (express, ws)