@spec base_url() :: String.t()

Returns the base URL for BrasilAPI.

Can be overridden via application environment or system environment.

@spec req_options() :: keyword()

Returns additional Req options for HTTP requests.

Automatically disables retries in test environment for faster tests.

@spec retry_attempts() :: non_neg_integer()

Returns the number of retry attempts for failed requests.

@spec timeout() :: pos_integer()

Returns the request timeout in milliseconds.