dsh-workbuddy: Wordless-Style Theme for DeepSeek Harness

`dsh-workbuddy` is a theme plugin designed for DeepSeek Harness (DSH), aiming to replace the default interface with a Wordless-style experience by injecting slots to override styles. The plugin applies visual customization to the brand mark and workspace menu, including a Lime-gradient brand block and a sticky-position flip menu, while fully preserving the native Web editor and selector chips. It supports complete keyboard navigation, allowing operation via arrow keys and Home/End keys, and also supports character input for quick lookup. Additionally, the plugin completes the missing host-side workspace creation callback through child slots. Licensed under the MIT License, it independently manages its lifecycle via the `ctx.slots.inject` mechanism to achieve lightweight interface customization.