用 EveryInfra 的 crosscheck 检索核实一个具体事实，或产出带出处的研究结论。用户要求核实、求证、查证某个说法，需要可靠出处，或要比较多个来源是否一致时使用。
Install
The individual skill folder is not confirmed. This command opens the repository’s skill selector; follow the upstream instructions.
skills CLI
npx skills add everyinfra/everyinfra-agent-plugins