Function deploy_staged 

pub fn deploy_staged(
    action: &FileAction,
    staging_dir: &Path,
    target_dir: &Path,
    dry_run: bool,
    force: bool,
    rendered_content: Option<&str>,
) -> Result<DeployResult>

Deploy a file action via staging: copy/render the real file into staging_dir, then create a symlink from target_dir pointing to the staged file.

For all entry kinds (Base, Override, Template), the staged file is a real file. The target path is always a symlink to the staged file’s canonical path.