Function remote_install_payload 

pub fn remote_install_payload(
    runner: &dyn ProcessRunner,
    opts: &RemoteOptions,
    bins: &LocalBins,
    choice: EcosystemInstallChoice,
) -> Result<Option<String>>

Copy CLI + TUI + status-api (+ MCP when present) into install_dir and enable units.

Missing horto-os-ui-mcp skips MCP transfer/enable; other units still install. Returns the captured hex bearer when the drop file can be read.

Errors

Returns crate::HortoError when transfer or remote enable fails.