dsh-model-vendor-badge: Displaying the Current Model Vendor in DeepSeek Harness

`dsh-model-vendor-badge` is a DeepSeek Harness plugin developed by Townrain. It displays the provider behind the current model to the left of the Web compiler's model selector. The plugin is registered under `conversation.input.right`, reads the same `ModelDirectory` data source as the session, and updates the vendor pill display in real time. Known providers are shown with a brand-colored dot, while unknown ones use a neutral dot. Installation uses the `dsh plugin` command, and building depends on a local DeepSeek Harness repository. The plugin runs entirely on the client and leaves no residue after uninstallation.