### 修复
- **技能发现性能**：在递归扫描技能时跳过 `node_modules` 目录。修复了当技能目录包含 npm 依赖项时导致的约 60ms 启动延迟问题。
### 新增
- **启动计时分析**：设置 `PI_TIMING=1` 可查看启动性能分解（仅限交互模式）。
### Fixed
- **Skill discovery performance**: Skip `node_modules` directories when recursively scanning for skills. Fixes ~60ms startup delay when skill directories contain npm dependencies.
### Added
- **Startup timing instrumentation**: Set `PI_TIMING=1` to see startup performance breakdown (interactive mode only).