Add a Specification-Driven Closed Loop to DeepSeek Harness with dsh-spec-loop

`dsh-spec-loop` is a DeepSeek Harness community plugin (MIT license, current version v0.1.2) maintained by tianji-qingtian. It uses the `/spec` command family to drive the workflow of "generate specification → approve → implement → one-by-one acceptance → archive". Its change directory is compatible with the openspec/ layout of OpenSpec, and it comes with format verification and approval gates, with change cards displayed above the Web UI input box. This article checks the installation commands, typical usage and permission boundaries by comparing the catalog page with the GitHub repository.