mimo-vision: DSH Native Vision Plugin

mimo-vision is a native plugin designed for DeepSeek Harness (DSH), providing text description capabilities for host models that lack native vision support. As a first-class citizen of DSH, it registers the `describe_image` tool and uses DSH infrastructure to manage dependencies and credentials, sending images to a multimodal model and parsing the resulting descriptions. The plugin supports routing to free or paid APIs, preferring free APIs by default, and can be installed with the command `dsh plugin --profile web add mimo-vision`. It requires Node.js `^22.19` or `>=24`, and an OpenCode API Key must be configured. When used, the host model can invoke the tool to generate text descriptions for images at specified paths.