dsh-reject-message: DeepSeek Harness Plugin Completing the Plan Review Rejection Workflow

`dsh-reject-message` is a Web plugin for DeepSeek Harness that addresses the limited rejection feedback provided by the native Plan review card. It takes over the elevation window and adds a rejection entry point, allowing users to provide a description. This description is appended to the tool error result as `plugin additionalContext`, enabling the model to obtain the specific reason for rejection. The plugin supports both Web and Desktop; after installation, press `Enter` to allow and `Escape` to reject, and the engine version must be at least 0.2.0-rc.1.