Function install_skill 

pub fn install_skill(
    target_dir: &Path,
    content: &str,
    dry_run: bool,
) -> Result<SkillResult, CliError>

Install the Seshat skill file into an agent’s skills directory.

target_dir should be e.g. ~/.claude/skills/seshat/ or ~/.config/opencode/skills/seshat/. The function creates the directory if absent and always overwrites SKILL.md (versioned via binary release).