dsh-tidy-display: Unified Reading View and Message Track for Long Conversations

The `dsh-tidy-display` plugin for DeepSeek Harness (DSH) is designed to address the challenges of difficult skimming and complex navigation in long conversations by consolidating the original reading and navigation features. Key features include: a reading view that collapses the reasoning process, streams responses, and applies translucent visual optimizations; and a message rail providing canvas-based navigation, with support for fisheye hover, summary cards, and custom styling. Before installing, any conflicting plugins must be removed. The plugin supports host versions 0.1.0–0.2.0; for older versions, installation requires specifying a tag.