diff --git a/crates/miroir-core/src/session_pinning.rs b/crates/miroir-core/src/session_pinning.rs
index 1a772f5..1209185 100644
--- a/crates/miroir-core/src/session_pinning.rs
+++ b/crates/miroir-core/src/session_pinning.rs
@@ -375,9 +375,13 @@ impl SessionManager {
     }
 
     /// Update the session active count metric.
+    ///
+    /// Note: This must be called from an async context since it uses
+    /// try_read() to avoid blocking the runtime.
     pub fn update_metrics(&self, active_count_fn: impl FnOnce(usize)) {
-        let count = self.sessions.blocking_read().len();
-        active_count_fn(count);
+        if let Ok(guard) = self.sessions.try_read() {
+            active_count_fn(guard.len());
+        }
     }
 
     /// Check if session pinning is enabled.
diff --git a/crates/miroir-proxy/src/main.rs b/crates/miroir-proxy/src/main.rs
index 22627eb..12723de 100644
--- a/crates/miroir-proxy/src/main.rs
+++ b/crates/miroir-proxy/src/main.rs
@@ -164,6 +164,7 @@ impl FromRef<UnifiedState> for admin_endpoints::AppState {
             alias_registry: state.admin.alias_registry.clone(),
             leader_election: state.admin.leader_election.clone(),
             mode_c_worker: state.admin.mode_c_worker.clone(),
+            replica_selector: state.admin.replica_selector.clone(),
         }
     }
 }
diff --git a/crates/miroir-proxy/src/routes/admin_endpoints.rs b/crates/miroir-proxy/src/routes/admin_endpoints.rs
index 25d667e..16613d9 100644
--- a/crates/miroir-proxy/src/routes/admin_endpoints.rs
+++ b/crates/miroir-proxy/src/routes/admin_endpoints.rs
@@ -336,6 +336,8 @@ pub struct AppState {
     pub leader_election: Option<Arc<LeaderElection>>,
     /// Mode C worker for chunked background jobs (plan §14.5 Mode C).
     pub mode_c_worker: Option<Arc<ModeCWorker>>,
+    /// Adaptive replica selector (plan §13.3).
+    pub replica_selector: Arc<miroir_core::replica_selection::ReplicaSelector>,
 }
 
 impl AppState {
@@ -631,6 +633,7 @@ impl AppState {
             alias_registry,
             leader_election,
             mode_c_worker,
+            replica_selector: Arc::new(miroir_core::replica_selection::ReplicaSelector::default()),
         }
     }
 
diff --git a/miroir.yaml b/miroir.yaml
index 9d229be..0e06a3f 100644
--- a/miroir.yaml
+++ b/miroir.yaml
@@ -2,6 +2,9 @@
 shards: 64
 replication_factor: 1
 replica_groups: 1
+master_key: "test-master-key"
+admin:
+  api_key: "test-admin-key"
 task_store:
   backend: sqlite
   path: /tmp/miroir-tasks-test.db
@@ -12,3 +15,25 @@ search_ui:
   enabled: false
 admin_ui:
   enabled: false
+cdc:
+  enabled: false
+multi_search:
+  enabled: false
+vector_search:
+  enabled: false
+ttl:
+  enabled: false
+tenant_affinity:
+  enabled: false
+shadow:
+  enabled: false
+ilm:
+  enabled: false
+canary_runner:
+  enabled: false
+explain:
+  enabled: false
+hpa:
+  enabled: false
+leader_election:
+  enabled: false