// src/debug_hook.rs
// Per-frame injection point for the debug subsystem.
//
// The run loop (`crate::run`) owns the world loop but knows nothing about
// debugging. A `DebugHook` is an optional per-frame callback it invokes on the
// main thread; the only implementation is `crate::debug::DebugServer`. The
// trait stays `pub(crate)` so it is not part of any public surface.
use crateApp;
use crateWorld;
use ShutdownToken;
pub