/// Store an API key in the OS keychain.
/// Stub implementation using environment variables until keyring crate is added.
pub fn store_api_key(provider: &str, key: &str) {
    std::env::set_var(
        format!("KON_API_KEY_{}", provider.to_uppercase()),
        key,
    );
}

/// Retrieve an API key from the OS keychain.
/// Stub implementation using environment variables until keyring crate is added.
pub fn retrieve_api_key(provider: &str) -> Option<String> {
    std::env::var(format!("KON_API_KEY_{}", provider.to_uppercase())).ok()
}