dsh-prompt-optimize: Rewrite Draft in Web Composer

`dsh-prompt-optimize` is a DeepSeek Harness web plugin designed to help LLMs polish draft prompts before messages are sent. Its core features include side-effect-free rewriting, Sparkle button visibility control, and smart status detection. Installation requires adding it via the command line and configuring `allowBuilds` or using a local path. The plugin runs with process-level permissions, emphasizes source-code security and required configuration, and is suitable for scenarios where prompts need to be optimized before sending.