usestd::sync::OnceLock;staticAPI_KEY:OnceLock<String>=OnceLock::new();/// Initializes the OpenAI client with the given API key.
/// This must be called before any API functions.
pubfnopenai_init(key:&str){let_=API_KEY.set(key.to_string());}/// Internal helper to get the API key.
/// Returns None if `openai_init` was not called.
pub(crate)fnget_api_key()->Option<&'staticstr>{API_KEY.get().map(|s|s.as_str())}