Function load_package 

pub async fn load_package(
    state: &ServerState,
    caller: &CallerIdentity,
    transport: &'static str,
    archive: Vec<u8>,
) -> Result<ProtoLoadPackageResponse, DeployApiError>

Handles a deploy archive upload (LoadPackage / POST /deploy/packages).

Idempotency is specified behavior: re-sending a resident archive succeeds with freshly_loaded = false, and route_changed reports whether the call re-pointed routing.

Errors

Returns DeployApiError for authorization denials, drain/shutdown refusals, oversized or malformed archives, the manifest-mismatch tripwire, and engine failures.