Function auth_request 

pub fn auth_request<T>(api_key: &str, body: T) -> Request<T>

Wrap a request body with Bearer API key authentication metadata.

All PCS External API calls require an API key in the Authorization header. This helper creates a tonic::Request<T> with the key pre-attached.

Example

let req = auth_request("pk_live_abc123", ExtGetOrCreateDmReq {
    target_ppnum: "77712345678".into(),
});