dsh-standard-toolkit: DeepSeek Harness Tool Manager

`dsh-standard-toolkit` is a plugin for DeepSeek Harness (DSH) designed to address the chaos in agent tool management, centered on the philosophy that "everything is a plugin." The plugin manages tools through a "tool staging area," loading them on demand only when triggered and automatically destroying them afterward, thereby saving tokens and preventing context pollution. It supports session isolation, two-level trigger-word matching, and security review mechanisms. Additionally, the plugin allows the model to create new tools on the fly via `register_new_tool` and provides an installation script to simplify the deployment process.