dsh-bundle-vision: Zero-Core-Change DeepSeek Harness Vision Capability

`dsh-bundle-vision` is a plugin package that provides vision capabilities for DeepSeek Harness (DSH). Through the Bundle patch mechanism, it mounts visual functionality to any Profile without modifying core code. The plugin registers the `describe_image` tool, which supports reading local images and invoking an external multimodal routing service. It relies on the file system, attachment service, and LLM calls, enabling pure text models to process images flexibly for agent development scenarios that require visual capabilities.