dsh-omc-tui: DeepSeek Harness Native Terminal TUI

`dsh-omc-tui` is the native terminal interaction plugin for DeepSeek Harness (DSH), designed to provide a full-featured TUI experience comparable to Claude Code. Built on independent viewports and differential rendering, it supports smooth wheel scrolling, intelligent selection, and input recovery, with four built-in themes and code highlighting. The plugin offers dual-mode vision (image pasting and Sidecar analysis), collapsible Thinking, a real-time task center, a global status bar, line-level security approval, and Danger Guard, effectively improving the efficiency of terminal development and task management.