Function run_extern_callback_with 

pub fn run_extern_callback_with<P, R>(
    format: &str,
    action: &str,
    fallback: R,
    body: impl FnOnce() -> R,
) -> R

Run a generic extern "C" callback body under std::panic::catch_unwind. Returns body’s value on a clean exit, fallback if the body panicked.

Same shape as run_audio_block_with but parameterized on action (e.g. "save_state", "load_state") so the panic log pinpoints which callback boundary fired. Use this for non-process FFI surfaces - state save / load, param formatting, anything the host calls through an extern "C" fn where a panic would unwind across an ABI that doesn’t promise abort-on-unwind.

Audio-thread process bodies should keep using run_audio_block / run_audio_block_with - the hardcoded "process()" label there keeps existing log lines stable.