DSH Plugin: Agent & Skill Management UI

The DeepSeek Harness (DSH) community plugin `dsh-agent-skill-manager` provides a web interface for intuitive management of Agent presets and Skill files. The plugin supports copying and deleting Agent presets and viewing a read-only list of Skills on the settings page. Installation requires DSH version 0.1.0-rc.6 or higher, and it can be used after a restart following installation. It is currently in the MVP stage and supports only basic management operations. Deleting a preset actually removes the local file, posing an unrecoverable risk.