dsh-timeline-studio-plugin: Integrating Timeline Studio's .timeline Command Layer into DeepSeek Harness

`dsh-timeline-studio-plugin` is an MIT-licensed plugin maintained by MartinDelophy, designed to connect DeepSeek Harness with Timeline Studio's deterministic `.timeline` command layer. It is not a new video editing interface, but rather enables AI to safely inspect, preview, apply modifications, and render MP4 files within conversations. Core features include packaging the `edit-timeline-studio` Agent Skill, providing seven tools that cover project, track, and transcript inspection, and reducing change risks through revision checks, idempotent operation IDs, and `allowedRoots` filesystem boundaries (including symlink escape protection).