dsh-rules-manager: Unified management of rules, slash commands, and skills in DSH

dsh-rules-manager (v1.7.0) is a DSH workflow plugin maintained by jilian-dsh. It manages $DSH_HOME/AGENTS.md rules, read-only command lists, custom commands with {input}, and enables/disables or moves skills to the trash via the `/rules` command and the "Rules, Commands, and Skills" panel in the Settings page. It also supports automatic backup and one-click restore. Recommended installation: `dsh plugin --profile web add dsh-rules-manager`. Requires Node >= 22, has high permissions, and you should review the security design before installation.