Attribute Macro async_trait 

#[async_trait]

Re-export of the [async_trait] crate so users can write #[async_trait] on their own trait impls (e.g. domain::domain_service::DomainService, domain::eventing::EventHandler) without adding a direct async-trait dependency.

The accompanying attribute-macro re-export lives in the macro namespace (see async_trait!) so use eventide::async_trait; followed by #[async_trait] works out of the box.