core: add metering extension seam

TASKS.md

@@ -166,4 +166,5 @@ Progress:
   - Phase 2 dependency slice: `IdentityProvider` seam widened to cover `SSO/TOTP` with default `NotSupportedForProvider` methods and shared public DTOs for authorize/callback/two-factor flows; workspace version bumped to `0.3.0` for downstream enterprise consumption
   - Phase 2 dependency slice: `apps/admin-api` now exposes a reusable lib target (`src/lib.rs`), so downstream private repos can depend on `build_app`, `AppState`, `AdminServiceBuilder`, and auth/state modules without copying the Community admin app
   - Phase 3 dependency slice: added public tenancy seam in `crank-core` — `TenantId`, `TenantResolutionContext`, `TenantController`, `TenancyError`, and `SingleTenantController` — so `cloud` can build hosted tenant routing without bypassing the shared extension model
+  - Phase 3 dependency slice: added public metering seam in `crank-core` — `MeteringEvent`, `MeteringSink`, `SharedMeteringSink`, and `NoopMeteringSink` — so `cloud` can add hosted usage capture without introducing private-only contracts
   - backward-compatible alias `CommunityMachineCredentialVerifier` сохранен, поведение Community не изменено

crates/crank-core/src/ext/metering.rs

@@ -0,0 +1,55 @@
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use time::OffsetDateTime;
+
+use crate::{AgentId, InvocationSource, InvocationStatus, OperationId, WorkspaceId};
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct MeteringEvent {
+    pub workspace_id: WorkspaceId,
+    pub agent_id: Option<AgentId>,
+    pub operation_id: OperationId,
+    pub source: InvocationSource,
+    pub status: InvocationStatus,
+    pub duration_ms: u64,
+    pub created_at: OffsetDateTime,
+}
+
+#[async_trait]
+pub trait MeteringSink: Send + Sync {
+    async fn record(&self, event: MeteringEvent);
+}
+
+pub type SharedMeteringSink = Arc<dyn MeteringSink>;
+
+#[derive(Clone, Copy, Debug, Default)]
+pub struct NoopMeteringSink;
+
+#[async_trait]
+impl MeteringSink for NoopMeteringSink {
+    async fn record(&self, _event: MeteringEvent) {}
+}
+
+#[cfg(test)]
+mod tests {
+    use time::OffsetDateTime;
+
+    use super::{MeteringEvent, MeteringSink, NoopMeteringSink};
+    use crate::{InvocationSource, InvocationStatus, OperationId, WorkspaceId};
+
+    #[tokio::test]
+    async fn noop_metering_sink_accepts_event() {
+        NoopMeteringSink
+            .record(MeteringEvent {
+                workspace_id: WorkspaceId::new("ws_01"),
+                agent_id: None,
+                operation_id: OperationId::new("op_01"),
+                source: InvocationSource::AgentToolCall,
+                status: InvocationStatus::Ok,
+                duration_ms: 42,
+                created_at: OffsetDateTime::now_utc(),
+            })
+            .await;
+    }
+}

crates/crank-core/src/ext/mod.rs

@@ -2,5 +2,6 @@ pub mod access;
 pub mod audit;
 pub mod auth;
 pub mod capability;
+pub mod metering;
 pub mod protocol;
 pub mod tenancy;

crates/crank-core/src/lib.rs

@@ -48,6 +48,7 @@ pub use ext::auth::{
     TwoFactorPendingIdentity, TwoFactorSetup, TwoFactorStatus, VerifiedMachineCredential,
 };
 pub use ext::capability::{CapabilityProfile, CommunityCapabilityProfile};
+pub use ext::metering::{MeteringEvent, MeteringSink, NoopMeteringSink, SharedMeteringSink};
 pub use ext::protocol::{
     AdapterRegistry, AdapterResponse, PreparedRequest, ProtocolAdapter, ProtocolAdapterError,
     ResponseCacheScope, RuntimeRequestContext, SharedProtocolAdapter, WindowExecutionResult,