ax(node): rename dedup field to deduplicator in Transport struct

AX Principle 1: predictable names over short names. The abbreviated
struct field `dedup` requires a reader to mentally expand it; the
full name `deduplicator` is self-describing.

Co-Authored-By: Charon <charon@lethean.io>

pkg/node/transport.go

@@ -110,7 +110,7 @@ type Transport struct {
 	node         *NodeManager
 	registry     *PeerRegistry
 	handler      MessageHandler
-	dedup        *MessageDeduplicator // Message deduplication
+	deduplicator *MessageDeduplicator // Message deduplication
 	mutex        sync.RWMutex
 	ctx          context.Context
 	cancel       context.CancelFunc
@@ -180,7 +180,7 @@ func NewTransport(node *NodeManager, registry *PeerRegistry, config TransportCon
 		node:     node,
 		registry: registry,
 		conns:    make(map[string]*PeerConnection),
-		dedup:    NewMessageDeduplicator(5 * time.Minute), // 5 minute TTL for dedup
+		deduplicator: NewMessageDeduplicator(5 * time.Minute), // 5 minute TTL for dedup
 		upgrader: websocket.Upgrader{
 			ReadBufferSize:  1024,
 			WriteBufferSize: 1024,
@@ -268,7 +268,7 @@ func (t *Transport) Start() error {
 			case <-t.ctx.Done():
 				return
 			case <-ticker.C:
-				t.dedup.Cleanup()
+				t.deduplicator.Cleanup()
 			}
 		}
 	}()
@@ -756,11 +756,11 @@ func (t *Transport) readLoop(pc *PeerConnection) {
 		}
 
 		// Check for duplicate messages (prevents amplification attacks)
-		if t.dedup.IsDuplicate(msg.ID) {
+		if t.deduplicator.IsDuplicate(msg.ID) {
 			logging.Debug("dropping duplicate message", logging.Fields{"msg_id": msg.ID, "peer_id": pc.Peer.ID})
 			continue
 		}
-		t.dedup.Mark(msg.ID)
+		t.deduplicator.Mark(msg.ID)
 
 		// Rate limit debug logs in hot path to reduce noise (log 1 in N messages)
 		if debugLogCounter.Add(1)%debugLogInterval == 0 {