dsh-workspace-kit: Soft Archiving and Enhanced Sidebar

`dsh-workspace-kit` is a plugin developed for DeepSeek Harness (DSH) to address limitations in the native sidebar’s workspace search, archiving, and customization. It provides an enhanced sidebar with Spotlight-style quick search, a soft archiving mechanism (persistent and recoverable), drag-and-drop reordering, and customizable styling (32 icons / 9 colors). Using `⌘K` or the sidebar search box, users can efficiently manage workspaces and sessions, with one-click switching back to the official sidebar. Once installed, the plugin takes effect automatically, optimizing the workspace management experience.