dsh-image-describer: Equipping DeepSeek Harness's Text-Only Models with Visual Understanding Capabilities

The `dsh-image-describer` plugin in DeepSeek Harness (DSH) intercepts the message stream and converts image content into structured text, enabling text-only LLMs to understand images. It supports dual-mode interaction, including pasting images into the chat box (attachment mode) and referencing local file paths in the conversation (Tool mode), and automatically performs OCR and content recognition. Before use, enable the image input channel for the text model in the configuration file and specify a multimodal vision model, such as MiniMax-M3, along with its API key.