7dgroup-ai/dsh-skill-7d-git-commit: Validate 7DGroup commit specifications in DSH sessions

`7dgroup-ai/dsh-skill-7d-git-commit` is a DSH composite layer plugin (v0.1.0-rc.3, MIT licensed) designed to integrate Git commit convention checks directly into the DSH session. Before executing `git commit`, it performs client-side validation of commit messages based on 7DGroup standards to ensure compliance with team conventions. Core validation rules include: titles must follow the "[Type] Brief Description" format, with no more than 50 characters after the tag and no punctuation at the end; the body is restricted to 70 characters per line and only allows numbered lists; and specific characters and forbidden phrases such as "TODO" are strictly prohibited. The plugin supports 9 Chinese type tags and allows for emergency deployment exemptions. Installation requires Node ^22.19+, pnpm 10+, and specific pnpm configurations.