dsh-plugin-pi-ui: Redesigning the DeepSeek Harness Web Interface Sidebar

dsh-plugin-pi-ui is a sidebar plugin for the DeepSeek Harness Web interface designed to enhance the efficiency of session and file management. The plugin refactors the left sidebar into a temporary session area, a working directory selector, and a session list area. It supports creating drafts that take effect only after sending, filtering sessions by directory, and taking over the right column to display a compact file browser. The plugin must be installed via command and requires a service restart. Its settings and file explorer are memory-level and are reset after a page refresh.