dsh-simple-cli: Add a Claude Code-like terminal chat to DeepSeek Harness

# Foreword Developers who work in the command line for a long time often have this requirement: input a sentence directly in the terminal to see the model's response in a streaming format, the tool execution process in real-time, and manually confirm sensitive operations—instead of switching to a browser or assembling outputs from headless calls. DeepSeek Harness (hereinafter referred to as dsh) supports specifying a profile at startup (e.g., `dsh --profile cli`). The dsh-simple-cli introduced below is a CLI profile that runs entirely within the terminal: once installed, use the `dsh-cli` command to converse with the Agent, resembling the interface of Claude Code. # What is dsh-simple-cli