dsh-fschannel: Enabling two-way communication between DeepSeek Harness Web sessions and Feishu bots

dsh-fschannel is a DeepSeek Harness (DSH) plugin that utilizes the official Lark/Feishu WebSocket SDK to establish a long-lived connection, bridging DSH web sessions with Feishu/Lark chat without requiring public network callbacks. The plugin supports one-to-one persistent binding between web sessions and Feishu chats to enable message interoperability. Core features include SDK-based deduplication and serialized message delivery, Markdown-based streaming card output (automatically falling back to regular messages if permissions are insufficient), image recognition processing integrated with the vision toolkit, and the ability to send images or files to Feishu. Additionally, the plugin offers Feishu-side commands that allow switching models, adjusting thinking intensity, viewing status, and stopping tasks via commands or card buttons. Installation requires Node 22.19+, dsh CLI, and pnpm.