skillx: Secure External Skill Adoption Plugin for DeepSeek Harness

SkillX is a security meta-skill and DeepSeek Harness plugin designed for AI Agents, aiming to standardize the discovery, evaluation, and secure adoption processes of external skills. It requires the Agent to determine the need for external assistance when executing tasks, prioritize local resource checks, and then search for candidates based on channel priority. By retrieving candidates in a read-only manner and cross-comparing their relevance, it identifies security and trust risks such as prompt injection. If medium-to-high risks or red flags are detected, user confirmation is mandatory; by default, it is used only as a temporary reference, while permanent installation requires a stricter process. This plugin can be installed via the `dsh plugin --profile web add` command (package name: `dsh-skillx`) and uninstalled using the `remove` command.