dsh-todo-extract: TODO/FIXME Extraction Plugin

DSH Harness provides a plugin mechanism to simplify task marker extraction. `dsh-todo-extract` is a client plugin maintained by user uckkk that extracts TODO/FIXME markers from text. The plugin is implemented purely in Node.js and requires no network connection or external services. Once installed, it can call a registered tool within a session to retrieve markers. Since the plugin runs locally, it is recommended to review its source code before installation to verify security.