Macro dev_log 

macro_rules! dev_log {
    ($Tag:expr, $($Arg:tt)*) => { ... };
}

Tag-gated dev log. Compiled out in release builds via cfg!(debug_assertions) short-circuit.

The body of the macro lives in this crate’s log crate facade so the embedder’s logger decides routing. Mountain’s tracing subscriber + Air’s env_logger both pick this up automatically without further wiring.