Function validate_posture_patch 

pub fn validate_posture_patch(
    patch: &[PosturePatchEntry],
) -> Result<(), CliError>

Client-side wire hygiene for a posture patch: no unknown cordon_* key and no empty patch. Mirrors the host’s handle_fleet_posture_op guard messages; the host’s typed PosturePolicyPatch::validate remains the value authority.

Errors

CliError::OperatorHygiene with the refused key list or the empty-patch message.