dsh-tint: Color Brightening

dsh-tint is a DeepSeek Harness plugin maintained by uckkk, focused on color brightening. It is implemented in pure Node.js and has no network dependencies. The installation command is `dsh plugin add github:uckkk/dsh-tint`. The plugin runs with the current process permissions, is released under the MIT License, and is suitable for scenarios that require color processing in DSH.