/// Delegate protocol for `{{ box_name }}`.
/// Conforming types convert raw FFI params (RustString etc.) to user-friendly
/// Swift types and return a JSON-encoded result string.
/// Implemented by the private adapter class in the `{{ trait_name }}` module.
///
/// Leading `_` flags this as an internal binding surface — not part of the
/// user-facing API. Must remain `public` because Swift requires public visibility
/// for cross-module protocol conformance (implementer lives in the main target).
public protocol {{ delegate_protocol_name }}: AnyObject {
