fix(release): 将 skills/ 目录打入 Portal runtime 产物

生产 Agent 需从 live 目录读取平台技能（含 docx-generate），无源码 runtime 必须携带 skills 树。

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/build-portal-runtime.mjs

@@ -131,6 +131,12 @@ async function copyRuntimeAssets() {
   if (await exists(schemaFile)) {
     await fs.copyFile(schemaFile, path.join(runtimeRoot, 'schema.sql'));
   }
+
+  const skillsDir = path.join(root, 'skills');
+  if (await exists(skillsDir)) {
+    console.log('==> 拷贝平台 skills 目录');
+    await copyDir(skillsDir, path.join(runtimeRoot, 'skills'));
+  }
 }
 
 async function copyNodeModules() {
@@ -233,6 +239,8 @@ async function writeMetadata() {
       'Bundled alongside server.mjs (required for sandbox-fs MCP):',
       '  mindspace-sandbox-mcp.mjs  (esbuild bundle; includes schedule-service deps)',
       '',
+      'Platform agent skills (synced into user workspaces):',
+      '  skills/',
       'Key runtime differences must stay in .env, not in the artifact:',
       '  DATABASE_URL / MYSQL_*',
       '  H5_PUBLIC_BASE_URL',