@spec callback_timeout() :: integer()

Returns the default callback timeout in milliseconds.

@spec max_hard_turns() :: integer()

Returns the hard upper bound for max-turn validation.

@spec max_input_length() :: integer()

Returns the maximum allowed general input length.

@spec max_prompt_length() :: integer()

Returns the maximum allowed custom prompt length.

@spec validate_and_sanitize_prompt(prompt()) :: {:ok, prompt()} | {:error, atom()}

Validates prompt input and returns a sanitized version.

@spec validate_and_wrap_callback(
  callback(),
  keyword()
) :: {:ok, callback()} | {:error, atom()}

Validates and wraps callbacks with timeout protection.

@spec validate_callback(callback()) :: validation_result()

Validates callback arity and type.

Wrapped callbacks are invoked with a single argument, so only arity-1 callbacks are valid.

@spec validate_custom_prompt(
  prompt(),
  keyword()
) :: {:ok, prompt()} | {:error, atom()}

Validates custom prompts used for system-level behavior.

@spec validate_max_turns(integer()) :: {:ok, integer()} | {:error, atom()}

Validates and caps requested max-turn counts.

@spec validate_prompt(prompt()) :: validation_result()

Validates prompt input without transforming it.

@spec validate_string(
  String.t() | nil,
  keyword()
) :: {:ok, String.t()} | {:error, atom()}

Validates generic string input with length and control-byte checks.