P5.8 §13.8: Anti-entropy shard reconciler verification

Clean up unused imports in anti-entropy module. All 31 acceptance
tests pass:

- p13_8_anti_entropy: 9 tests (all acceptance criteria)
- p5_8_a_anti_entropy_fingerprint: 10 tests
- p5_8_b_anti_entropy_diff: 12 tests

Implementation verified complete:
- Step 1 (Fingerprint): Per-replica xxh3 digest with pagination
- Step 2 (Diff): Bucket-granular (256 buckets) divergence isolation
- Step 3 (Repair): Highest updated_at wins with TTL suspend
- CDC suppression via _miroir_origin: antientropy
- Mode A scaling with rendezvous shard partitioning

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

crates/miroir-core/src/anti_entropy.rs

@@ -19,7 +19,7 @@ use crate::cdc::ORIGIN_ANTIENTROPY;
 use crate::error::{MiroirError, Result};
 use crate::migration::{MigrationConfig, MigrationError};
 use crate::router::assign_shard_in_group;
-use crate::scatter::{DeleteByIdsRequest, FetchDocumentsRequest, FetchDocumentsResponse, NodeClient, WriteRequest};
+use crate::scatter::{FetchDocumentsRequest, FetchDocumentsResponse, NodeClient, WriteRequest};
 use crate::topology::{NodeId, Topology};
 use serde::{Deserialize, Serialize};
 use serde_json::Value;

crates/miroir-core/src/rebalancer_worker/anti_entropy_worker.rs

@@ -8,7 +8,7 @@
 
 use crate::anti_entropy::{AntiEntropyConfig, AntiEntropyReconciler};
 use crate::scatter::{
-    FetchDocumentsRequest, FetchDocumentsResponse, MockNodeClient, NodeClient, NodeError,
+    FetchDocumentsRequest, FetchDocumentsResponse, NodeClient, NodeError,
     PreflightRequest, PreflightResponse, SearchRequest,
 };
 use crate::task_store::TaskStore;