DeepSeek Harness Plugin: dsh-im-hub-media Multi-Platform Instant Messaging Gateway

`dsh-im-hub-media` is a plugin designed specifically for DeepSeek Harness (DSH) to address the lack of "non-text" capabilities when interacting with mainstream IM platforms (Telegram, Feishu, and WeCom). It is open-sourced under the MIT license, with core features including multi-platform adapters (supporting speech-to-text, image/file receiving and distribution, and message card rendering), security isolation (whitelisting and session isolation), and credential resolution that depends on host services. By inserting a `MEDIA:/absolute/path` marker in a reply, the agent can automatically trigger the sending of media files. After installation, the service must be restarted and the adapters configured; this component effectively improves the interaction experience of cross-platform automated agents.