refactor(ecstore): route replication event host (#4126)

crates/ecstore/src/bucket/replication/README.md

@@ -12,7 +12,7 @@ and lifecycle/heal scheduling paths.
 | `config.rs` | Replication config helpers, rule matching, and tag filtering. | Uses replication-local filemeta/tagging boundaries and S3 DTOs directly. |
 | `datatypes.rs` | Replication status and operation DTOs. | Publicly re-exported through the ECStore replication facade. |
 | `replication_pool.rs` | Replication queue, worker pool, MRF persistence, bucket stats, and delete/object scheduling. | Depends on bucket target sys, bucket metadata sys, metadata paths, and file metadata replication contracts through local boundaries, config storage, storage contracts through the replication storage boundary, runtime sources, and notification state. |
-| `replication_resyncer.rs` | Object replication, delete replication, resync, MRF encode/decode, target calls, and multipart target upload paths. | Depends on target calls and target config types through the replication target boundary, metadata paths and metadata systems through the replication metadata boundary, file metadata replication contracts through the filemeta boundary, versioning systems, storage contracts through the replication storage boundary, runtime sources, notification events, bandwidth reader wrapping, and SetDisks lock timing. |
+| `replication_resyncer.rs` | Object replication, delete replication, resync, MRF encode/decode, target calls, and multipart target upload paths. | Depends on target calls and target config types through the replication target boundary, metadata paths and metadata systems through the replication metadata boundary, file metadata replication contracts through the filemeta boundary, versioning systems, storage contracts through the replication storage boundary, runtime sources, notification events and local event host selection through the event sink, bandwidth reader wrapping, and SetDisks lock timing. |
 | `replication_state.rs` | Replication queue/stat state and worker accounting. | Reads runtime sources and file metadata replication contracts through local boundaries, and owns shared replication pool/stat state. |
 | `rule.rs` | Rule evaluation helpers for object replication options. | Depends on ECStore replication object option types. |
 | `mod.rs` | Compatibility re-export facade for the current ECStore owner. | Must stay stable until downstream scanner, lifecycle, heal, and metrics paths compile through replacement contracts. |
@@ -28,7 +28,7 @@ and lifecycle/heal scheduling paths.
 | `ReplicationTargetStore` | Bucket target listing, target client lookup, target offline checks, target config types, and target operation option types. | Bucket target sys access, `BucketTargets`, and target operation types are concentrated in `replication_target_boundary.rs`. |
 | `ReplicationRuntime` | Worker pool, queue sizing, stats, bucket monitor, local node identity, cancellation, and admission state. | Direct runtime source/global access and shared replication pool/stat state. |
 | `ReplicationBandwidthLimiter` | Target reader wrapping for replication bandwidth accounting and throttling. | Direct bucket bandwidth reader imports from resyncer paths. |
-| `ReplicationEventSink` | Notification and audit events for skipped, failed, pending, and completed replication operations. | Direct event notification service calls from worker code. |
+| `ReplicationEventSink` | Notification and audit events for skipped, failed, pending, and completed replication operations. | Event notification service calls and local event host selection are concentrated in `replication_event_sink.rs`. |
 | `ReplicationTagFilter` | Decode object tag strings for rule and metadata replication decisions. | Direct bucket tagging helper imports from replication workers. |
 | `ReplicationLifecycleBridge` | Lifecycle-originated delete and version-purge scheduling. | Direct coupling between lifecycle worker paths and replication delete scheduling. |