Newtype that lets us pass an `Arc<dyn MetricsSink>` into `ObservabilityPlugin::new(impl MetricsSink + 'static)` while keeping the caller-side type inf

Oneshot-backed receipt: `ack` sends `()` on the paired receiver, which unblocks the producer's `deliver_live` await.

Adapter to pass an `Arc<dyn MetricsSink>` into `ObservabilityPlugin::new(impl MetricsSink + 'static)`.

Minimal `ToolRegistry` for tests — `ToolRegistry::tool_ids` is the only entry point the permission filter walks. `get_tool` returns `None` because non

Newtype wrapper pinning `RouteModule` to `SystemRoutesState`. The trait would otherwise have nothing else to dispatch on for single-purpose state type

Track whether the tool was actually executed

Backend that delegates to a remote agent via A2A HTTP protocol.

Factory for the built-in A2A remote backend.