dsh-skill-matcher: DeepSeek Harness Skill and Expert Matching Plugin

`dsh-skill-matcher` is a Cordis plugin for DeepSeek Harness (DSH), designed to address the matching challenges agents face when invoking skills or experts. The plugin builds a unified index by scanning local environments and online open-source directories, provides tools such as `skill_matcher_scan`, `skill_matcher_match`, and `skill_matcher_list`, and supports automatic injection of guidance. Its core engine handles environment detection and data merging, and includes 13 built-in seed entries to enable offline use. The plugin is released under the MIT License, fetches JSON data only, and does not execute remote code, ensuring security and compliance. It is recommended to deploy it using the installation script in the project root directory.