ax(node): rename PeerRegistry receiver r to registry

AX Principle 1 — predictable names over short names.
The receiver `r` on PeerRegistry is a single-letter abbreviation;
all 29 methods now use `registry` for consistency with the rest of
the node package (controller, worker, transport all use full names).

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

pkg/node/peer.go

@@ -34,7 +34,7 @@ type Peer struct {
 	Connected bool `json:"-"`
 }
 
-// r.scheduleSave() // coalesces writes; disk flush at most once per saveDebounceInterval
+// registry.scheduleSave() // coalesces writes; disk flush at most once per saveDebounceInterval
 const saveDebounceInterval = 5 * time.Second
 
 // registry.SetAuthMode(PeerAuthAllowlist) // allow only pre-registered peers
@@ -157,50 +157,50 @@ func NewPeerRegistryWithPath(peersPath string) (*PeerRegistry, error) {
 
 // registry.SetAuthMode(PeerAuthAllowlist) // require pre-registration
 // registry.SetAuthMode(PeerAuthOpen)      // allow any peer (default)
-func (r *PeerRegistry) SetAuthMode(mode PeerAuthMode) {
-	r.allowedPublicKeyMutex.Lock()
-	defer r.allowedPublicKeyMutex.Unlock()
-	r.authMode = mode
+func (registry *PeerRegistry) SetAuthMode(mode PeerAuthMode) {
+	registry.allowedPublicKeyMutex.Lock()
+	defer registry.allowedPublicKeyMutex.Unlock()
+	registry.authMode = mode
 	logging.Info("peer auth mode changed", logging.Fields{"mode": mode})
 }
 
 // if registry.GetAuthMode() == PeerAuthAllowlist { /* enforce allowlist */ }
-func (r *PeerRegistry) GetAuthMode() PeerAuthMode {
-	r.allowedPublicKeyMutex.RLock()
-	defer r.allowedPublicKeyMutex.RUnlock()
-	return r.authMode
+func (registry *PeerRegistry) GetAuthMode() PeerAuthMode {
+	registry.allowedPublicKeyMutex.RLock()
+	defer registry.allowedPublicKeyMutex.RUnlock()
+	return registry.authMode
 }
 
 // registry.AllowPublicKey(peer.PublicKey) // permit this key without pre-registration
-func (r *PeerRegistry) AllowPublicKey(publicKey string) {
-	r.allowedPublicKeyMutex.Lock()
-	defer r.allowedPublicKeyMutex.Unlock()
-	r.allowedPublicKeys[publicKey] = true
+func (registry *PeerRegistry) AllowPublicKey(publicKey string) {
+	registry.allowedPublicKeyMutex.Lock()
+	defer registry.allowedPublicKeyMutex.Unlock()
+	registry.allowedPublicKeys[publicKey] = true
 	logging.Debug("public key added to allowlist", logging.Fields{"key": safeKeyPrefix(publicKey)})
 }
 
 // registry.RevokePublicKey(peer.PublicKey) // block this key on next connect attempt
-func (r *PeerRegistry) RevokePublicKey(publicKey string) {
-	r.allowedPublicKeyMutex.Lock()
-	defer r.allowedPublicKeyMutex.Unlock()
-	delete(r.allowedPublicKeys, publicKey)
+func (registry *PeerRegistry) RevokePublicKey(publicKey string) {
+	registry.allowedPublicKeyMutex.Lock()
+	defer registry.allowedPublicKeyMutex.Unlock()
+	delete(registry.allowedPublicKeys, publicKey)
 	logging.Debug("public key removed from allowlist", logging.Fields{"key": safeKeyPrefix(publicKey)})
 }
 
 // if registry.IsPublicKeyAllowed(peer.PublicKey) { /* permit */ }
-func (r *PeerRegistry) IsPublicKeyAllowed(publicKey string) bool {
-	r.allowedPublicKeyMutex.RLock()
-	defer r.allowedPublicKeyMutex.RUnlock()
-	return r.allowedPublicKeys[publicKey]
+func (registry *PeerRegistry) IsPublicKeyAllowed(publicKey string) bool {
+	registry.allowedPublicKeyMutex.RLock()
+	defer registry.allowedPublicKeyMutex.RUnlock()
+	return registry.allowedPublicKeys[publicKey]
 }
 
 // if !registry.IsPeerAllowed(payload.Identity.ID, payload.Identity.PublicKey) { conn.Close(); return }
 // true when Open mode, or Allowlist mode with pre-registered peer or allowlisted key
-func (r *PeerRegistry) IsPeerAllowed(peerID string, publicKey string) bool {
-	r.allowedPublicKeyMutex.RLock()
-	authMode := r.authMode
-	keyAllowed := r.allowedPublicKeys[publicKey]
-	r.allowedPublicKeyMutex.RUnlock()
+func (registry *PeerRegistry) IsPeerAllowed(peerID string, publicKey string) bool {
+	registry.allowedPublicKeyMutex.RLock()
+	authMode := registry.authMode
+	keyAllowed := registry.allowedPublicKeys[publicKey]
+	registry.allowedPublicKeyMutex.RUnlock()
 
 	// Open mode allows everyone
 	if authMode == PeerAuthOpen {
@@ -208,9 +208,9 @@ func (r *PeerRegistry) IsPeerAllowed(peerID string, publicKey string) bool {
 	}
 
 	// Allowlist mode: check if peer is pre-registered
-	r.mutex.RLock()
-	_, isRegistered := r.peers[peerID]
-	r.mutex.RUnlock()
+	registry.mutex.RLock()
+	_, isRegistered := registry.peers[peerID]
+	registry.mutex.RUnlock()
 
 	if isRegistered {
 		return true
@@ -221,12 +221,12 @@ func (r *PeerRegistry) IsPeerAllowed(peerID string, publicKey string) bool {
 }
 
 // keys := registry.ListAllowedPublicKeys() // for display or export
-func (r *PeerRegistry) ListAllowedPublicKeys() []string {
-	r.allowedPublicKeyMutex.RLock()
-	defer r.allowedPublicKeyMutex.RUnlock()
+func (registry *PeerRegistry) ListAllowedPublicKeys() []string {
+	registry.allowedPublicKeyMutex.RLock()
+	defer registry.allowedPublicKeyMutex.RUnlock()
 
-	keys := make([]string, 0, len(r.allowedPublicKeys))
-	for key := range r.allowedPublicKeys {
+	keys := make([]string, 0, len(registry.allowedPublicKeys))
+	for key := range registry.allowedPublicKeys {
 		keys = append(keys, key)
 	}
 	return keys
@@ -234,22 +234,22 @@ func (r *PeerRegistry) ListAllowedPublicKeys() []string {
 
 // registry.AddPeer(&Peer{ID: "abc123", Name: "worker-1", Address: "10.0.0.2:9090", Role: RoleWorker})
 // Persistence is debounced — call Close() before shutdown to flush all pending writes.
-func (r *PeerRegistry) AddPeer(peer *Peer) error {
-	r.mutex.Lock()
+func (registry *PeerRegistry) AddPeer(peer *Peer) error {
+	registry.mutex.Lock()
 
 	if peer.ID == "" {
-		r.mutex.Unlock()
+		registry.mutex.Unlock()
 		return fmt.Errorf("peer ID is required")
 	}
 
 	// Validate peer name (P2P-LOW-3)
 	if err := validatePeerName(peer.Name); err != nil {
-		r.mutex.Unlock()
+		registry.mutex.Unlock()
 		return err
 	}
 
-	if _, exists := r.peers[peer.ID]; exists {
-		r.mutex.Unlock()
+	if _, exists := registry.peers[peer.ID]; exists {
+		registry.mutex.Unlock()
 		return fmt.Errorf("peer %s already exists", peer.ID)
 	}
 
@@ -261,54 +261,54 @@ func (r *PeerRegistry) AddPeer(peer *Peer) error {
 		peer.Score = 50 // Default neutral score
 	}
 
-	r.peers[peer.ID] = peer
-	r.rebuildKDTree()
-	r.mutex.Unlock()
+	registry.peers[peer.ID] = peer
+	registry.rebuildKDTree()
+	registry.mutex.Unlock()
 
-	return r.save()
+	return registry.save()
 }
 
 // registry.UpdatePeer(peer) // after handshake completes and real ID is known
 // Note: Persistence is debounced. Call Close() to flush before shutdown.
-func (r *PeerRegistry) UpdatePeer(peer *Peer) error {
-	r.mutex.Lock()
+func (registry *PeerRegistry) UpdatePeer(peer *Peer) error {
+	registry.mutex.Lock()
 
-	if _, exists := r.peers[peer.ID]; !exists {
-		r.mutex.Unlock()
+	if _, exists := registry.peers[peer.ID]; !exists {
+		registry.mutex.Unlock()
 		return fmt.Errorf("peer %s not found", peer.ID)
 	}
 
-	r.peers[peer.ID] = peer
-	r.rebuildKDTree()
-	r.mutex.Unlock()
+	registry.peers[peer.ID] = peer
+	registry.rebuildKDTree()
+	registry.mutex.Unlock()
 
-	return r.save()
+	return registry.save()
 }
 
 // registry.RemovePeer(peer.ID) // on manual disconnect or ban
 // Note: Persistence is debounced. Call Close() to flush before shutdown.
-func (r *PeerRegistry) RemovePeer(id string) error {
-	r.mutex.Lock()
+func (registry *PeerRegistry) RemovePeer(id string) error {
+	registry.mutex.Lock()
 
-	if _, exists := r.peers[id]; !exists {
-		r.mutex.Unlock()
+	if _, exists := registry.peers[id]; !exists {
+		registry.mutex.Unlock()
 		return fmt.Errorf("peer %s not found", id)
 	}
 
-	delete(r.peers, id)
-	r.rebuildKDTree()
-	r.mutex.Unlock()
+	delete(registry.peers, id)
+	registry.rebuildKDTree()
+	registry.mutex.Unlock()
 
-	return r.save()
+	return registry.save()
 }
 
 // peer := registry.GetPeer("abc123def456")
 // if peer == nil { return fmt.Errorf("peer not found") }
-func (r *PeerRegistry) GetPeer(id string) *Peer {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
+func (registry *PeerRegistry) GetPeer(id string) *Peer {
+	registry.mutex.RLock()
+	defer registry.mutex.RUnlock()
 
-	peer, exists := r.peers[id]
+	peer, exists := registry.peers[id]
 	if !exists {
 		return nil
 	}
@@ -319,12 +319,12 @@ func (r *PeerRegistry) GetPeer(id string) *Peer {
 }
 
 // for _, peer := range registry.ListPeers() { log(peer.ID, peer.Role) }
-func (r *PeerRegistry) ListPeers() []*Peer {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
+func (registry *PeerRegistry) ListPeers() []*Peer {
+	registry.mutex.RLock()
+	defer registry.mutex.RUnlock()
 
-	peers := make([]*Peer, 0, len(r.peers))
-	for _, peer := range r.peers {
+	peers := make([]*Peer, 0, len(registry.peers))
+	for _, peer := range registry.peers {
 		peerCopy := *peer
 		peers = append(peers, &peerCopy)
 	}
@@ -333,12 +333,12 @@ func (r *PeerRegistry) ListPeers() []*Peer {
 
 // registry.UpdateMetrics(peer.ID, rtt, peer.GeoKM, peer.Hops) // after PingPeer
 // Note: Persistence is debounced. Call Close() to flush before shutdown.
-func (r *PeerRegistry) UpdateMetrics(id string, pingMS, geoKM float64, hops int) error {
-	r.mutex.Lock()
+func (registry *PeerRegistry) UpdateMetrics(id string, pingMS, geoKM float64, hops int) error {
+	registry.mutex.Lock()
 
-	peer, exists := r.peers[id]
+	peer, exists := registry.peers[id]
 	if !exists {
-		r.mutex.Unlock()
+		registry.mutex.Unlock()
 		return fmt.Errorf("peer %s not found", id)
 	}
 
@@ -347,20 +347,20 @@ func (r *PeerRegistry) UpdateMetrics(id string, pingMS, geoKM float64, hops int)
 	peer.Hops = hops
 	peer.LastSeen = time.Now()
 
-	r.rebuildKDTree()
-	r.mutex.Unlock()
+	registry.rebuildKDTree()
+	registry.mutex.Unlock()
 
-	return r.save()
+	return registry.save()
 }
 
 // registry.UpdateScore(peer.ID, 75.0) // clamps to 0-100
 // Note: Persistence is debounced. Call Close() to flush before shutdown.
-func (r *PeerRegistry) UpdateScore(id string, score float64) error {
-	r.mutex.Lock()
+func (registry *PeerRegistry) UpdateScore(id string, score float64) error {
+	registry.mutex.Lock()
 
-	peer, exists := r.peers[id]
+	peer, exists := registry.peers[id]
 	if !exists {
-		r.mutex.Unlock()
+		registry.mutex.Unlock()
 		return fmt.Errorf("peer %s not found", id)
 	}
 
@@ -372,19 +372,19 @@ func (r *PeerRegistry) UpdateScore(id string, score float64) error {
 	}
 
 	peer.Score = score
-	r.rebuildKDTree()
-	r.mutex.Unlock()
+	registry.rebuildKDTree()
+	registry.mutex.Unlock()
 
-	return r.save()
+	return registry.save()
 }
 
 // registry.SetConnected(peer.ID, true)  // on connect
 // registry.SetConnected(peer.ID, false) // on disconnect or error
-func (r *PeerRegistry) SetConnected(id string, connected bool) {
-	r.mutex.Lock()
-	defer r.mutex.Unlock()
+func (registry *PeerRegistry) SetConnected(id string, connected bool) {
+	registry.mutex.Lock()
+	defer registry.mutex.Unlock()
 
-	if peer, exists := r.peers[id]; exists {
+	if peer, exists := registry.peers[id]; exists {
 		peer.Connected = connected
 		if connected {
 			peer.LastSeen = time.Now()
@@ -403,33 +403,33 @@ const (
 )
 
 // registry.RecordSuccess(peer.ID) // after a successful response
-func (r *PeerRegistry) RecordSuccess(id string) {
-	r.mutex.Lock()
-	peer, exists := r.peers[id]
+func (registry *PeerRegistry) RecordSuccess(id string) {
+	registry.mutex.Lock()
+	peer, exists := registry.peers[id]
 	if !exists {
-		r.mutex.Unlock()
+		registry.mutex.Unlock()
 		return
 	}
 
 	peer.Score = min(peer.Score+ScoreSuccessIncrement, ScoreMaximum)
 	peer.LastSeen = time.Now()
-	r.mutex.Unlock()
-	r.save()
+	registry.mutex.Unlock()
+	registry.save()
 }
 
 // registry.RecordFailure(peer.ID) // after a failed send or error response
-func (r *PeerRegistry) RecordFailure(id string) {
-	r.mutex.Lock()
-	peer, exists := r.peers[id]
+func (registry *PeerRegistry) RecordFailure(id string) {
+	registry.mutex.Lock()
+	peer, exists := registry.peers[id]
 	if !exists {
-		r.mutex.Unlock()
+		registry.mutex.Unlock()
 		return
 	}
 
 	peer.Score = max(peer.Score-ScoreFailureDecrement, ScoreMinimum)
 	newScore := peer.Score
-	r.mutex.Unlock()
-	r.save()
+	registry.mutex.Unlock()
+	registry.save()
 
 	logging.Debug("peer score decreased", logging.Fields{
 		"peer_id":   id,
@@ -439,18 +439,18 @@ func (r *PeerRegistry) RecordFailure(id string) {
 }
 
 // registry.RecordTimeout(peer.ID) // after a request deadline exceeded
-func (r *PeerRegistry) RecordTimeout(id string) {
-	r.mutex.Lock()
-	peer, exists := r.peers[id]
+func (registry *PeerRegistry) RecordTimeout(id string) {
+	registry.mutex.Lock()
+	peer, exists := registry.peers[id]
 	if !exists {
-		r.mutex.Unlock()
+		registry.mutex.Unlock()
 		return
 	}
 
 	peer.Score = max(peer.Score-ScoreTimeoutDecrement, ScoreMinimum)
 	newScore := peer.Score
-	r.mutex.Unlock()
-	r.save()
+	registry.mutex.Unlock()
+	registry.save()
 
 	logging.Debug("peer score decreased", logging.Fields{
 		"peer_id":   id,
@@ -460,12 +460,12 @@ func (r *PeerRegistry) RecordTimeout(id string) {
 }
 
 // for _, peer := range registry.GetPeersByScore() { log(peer.ID, peer.Score) }
-func (r *PeerRegistry) GetPeersByScore() []*Peer {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
+func (registry *PeerRegistry) GetPeersByScore() []*Peer {
+	registry.mutex.RLock()
+	defer registry.mutex.RUnlock()
 
-	peers := make([]*Peer, 0, len(r.peers))
-	for _, peer := range r.peers {
+	peers := make([]*Peer, 0, len(registry.peers))
+	for _, peer := range registry.peers {
 		peers = append(peers, peer)
 	}
 
@@ -483,11 +483,11 @@ func (r *PeerRegistry) GetPeersByScore() []*Peer {
 
 // peer := registry.SelectOptimalPeer()
 // if peer != nil { ctrl.ConnectToPeer(peer.ID) }
-func (r *PeerRegistry) SelectOptimalPeer() *Peer {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
+func (registry *PeerRegistry) SelectOptimalPeer() *Peer {
+	registry.mutex.RLock()
+	defer registry.mutex.RUnlock()
 
-	if r.kdTree == nil || len(r.peers) == 0 {
+	if registry.kdTree == nil || len(registry.peers) == 0 {
 		return nil
 	}
 
@@ -495,12 +495,12 @@ func (r *PeerRegistry) SelectOptimalPeer() *Peer {
 	// Score is inverted (100 - score) so lower is better in the tree
 	target := []float64{0, 0, 0, 0}
 
-	result, _, found := r.kdTree.Nearest(target)
+	result, _, found := registry.kdTree.Nearest(target)
 	if !found {
 		return nil
 	}
 
-	peer, exists := r.peers[result.Value]
+	peer, exists := registry.peers[result.Value]
 	if !exists {
 		return nil
 	}
@@ -511,22 +511,22 @@ func (r *PeerRegistry) SelectOptimalPeer() *Peer {
 
 // peers := registry.SelectNearestPeers(3) // top 3 peers by ping, hops, geo, score
 // for _, peer := range peers { ctrl.ConnectToPeer(peer.ID) }
-func (r *PeerRegistry) SelectNearestPeers(count int) []*Peer {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
+func (registry *PeerRegistry) SelectNearestPeers(count int) []*Peer {
+	registry.mutex.RLock()
+	defer registry.mutex.RUnlock()
 
-	if r.kdTree == nil || len(r.peers) == 0 {
+	if registry.kdTree == nil || len(registry.peers) == 0 {
 		return nil
 	}
 
 	// Target: ideal peer
 	target := []float64{0, 0, 0, 0}
 
-	results, _ := r.kdTree.KNearest(target, count)
+	results, _ := registry.kdTree.KNearest(target, count)
 
 	peers := make([]*Peer, 0, len(results))
 	for _, result := range results {
-		if peer, exists := r.peers[result.Value]; exists {
+		if peer, exists := registry.peers[result.Value]; exists {
 			peerCopy := *peer
 			peers = append(peers, &peerCopy)
 		}
@@ -536,12 +536,12 @@ func (r *PeerRegistry) SelectNearestPeers(count int) []*Peer {
 }
 
 // for _, peer := range registry.GetConnectedPeers() { ctrl.GetRemoteStats(peer.ID) }
-func (r *PeerRegistry) GetConnectedPeers() []*Peer {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
+func (registry *PeerRegistry) GetConnectedPeers() []*Peer {
+	registry.mutex.RLock()
+	defer registry.mutex.RUnlock()
 
 	peers := make([]*Peer, 0)
-	for _, peer := range r.peers {
+	for _, peer := range registry.peers {
 		if peer.Connected {
 			peerCopy := *peer
 			peers = append(peers, &peerCopy)
@@ -551,21 +551,21 @@ func (r *PeerRegistry) GetConnectedPeers() []*Peer {
 }
 
 // if registry.Count() == 0 { return ErrNoPeers }
-func (r *PeerRegistry) Count() int {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
-	return len(r.peers)
+func (registry *PeerRegistry) Count() int {
+	registry.mutex.RLock()
+	defer registry.mutex.RUnlock()
+	return len(registry.peers)
 }
 
-// r.rebuildKDTree() // called after AddPeer, UpdatePeer, RemovePeer, UpdateMetrics — lock must be held
-func (r *PeerRegistry) rebuildKDTree() {
-	if len(r.peers) == 0 {
-		r.kdTree = nil
+// registry.rebuildKDTree() // called after AddPeer, UpdatePeer, RemovePeer, UpdateMetrics — lock must be held
+func (registry *PeerRegistry) rebuildKDTree() {
+	if len(registry.peers) == 0 {
+		registry.kdTree = nil
 		return
 	}
 
-	points := make([]poindexter.KDPoint[string], 0, len(r.peers))
-	for _, peer := range r.peers {
+	points := make([]poindexter.KDPoint[string], 0, len(registry.peers))
+	for _, peer := range registry.peers {
 		// Build 4D point with weighted, normalized values
 		// Invert score so that higher score = lower value (better)
 		point := poindexter.KDPoint[string]{
@@ -588,35 +588,35 @@ func (r *PeerRegistry) rebuildKDTree() {
 		return
 	}
 
-	r.kdTree = tree
+	registry.kdTree = tree
 }
 
-// r.scheduleSave() // called by AddPeer, UpdatePeer, RemovePeer, UpdateMetrics, UpdateScore
+// registry.scheduleSave() // called by AddPeer, UpdatePeer, RemovePeer, UpdateMetrics, UpdateScore
 // Multiple writes within saveDebounceInterval are coalesced into one disk write.
-// Must NOT be called with r.mutex held.
-func (r *PeerRegistry) scheduleSave() {
-	r.saveMutex.Lock()
-	defer r.saveMutex.Unlock()
+// Must NOT be called with registry.mutex held.
+func (registry *PeerRegistry) scheduleSave() {
+	registry.saveMutex.Lock()
+	defer registry.saveMutex.Unlock()
 
-	r.dirty = true
+	registry.dirty = true
 
 	// If timer already running, let it handle the save
-	if r.saveTimer != nil {
+	if registry.saveTimer != nil {
 		return
 	}
 
 	// Start a new timer
-	r.saveTimer = time.AfterFunc(saveDebounceInterval, func() {
-		r.saveMutex.Lock()
-		r.saveTimer = nil
-		shouldSave := r.dirty
-		r.dirty = false
-		r.saveMutex.Unlock()
+	registry.saveTimer = time.AfterFunc(saveDebounceInterval, func() {
+		registry.saveMutex.Lock()
+		registry.saveTimer = nil
+		shouldSave := registry.dirty
+		registry.dirty = false
+		registry.saveMutex.Unlock()
 
 		if shouldSave {
-			r.mutex.RLock()
-			err := r.saveNow()
-			r.mutex.RUnlock()
+			registry.mutex.RLock()
+			err := registry.saveNow()
+			registry.mutex.RUnlock()
 			if err != nil {
 				// Log error but continue - best effort persistence
 				logging.Warn("failed to save peer registry", logging.Fields{"error": err})
@@ -625,18 +625,18 @@ func (r *PeerRegistry) scheduleSave() {
 	})
 }
 
-// r.mutex.RLock(); err := r.saveNow(); r.mutex.RUnlock()
-// Must be called with r.mutex held (at least RLock).
-func (r *PeerRegistry) saveNow() error {
+// registry.mutex.RLock(); err := registry.saveNow(); registry.mutex.RUnlock()
+// Must be called with registry.mutex held (at least RLock).
+func (registry *PeerRegistry) saveNow() error {
 	// Ensure directory exists
-	directoryPath := filepath.Dir(r.path)
+	directoryPath := filepath.Dir(registry.path)
 	if err := os.MkdirAll(directoryPath, 0755); err != nil {
 		return fmt.Errorf("failed to create peers directory: %w", err)
 	}
 
 	// Convert to slice for JSON
-	peers := make([]*Peer, 0, len(r.peers))
-	for _, peer := range r.peers {
+	peers := make([]*Peer, 0, len(registry.peers))
+	for _, peer := range registry.peers {
 		peers = append(peers, peer)
 	}
 
@@ -646,12 +646,12 @@ func (r *PeerRegistry) saveNow() error {
 	}
 
 	// Use atomic write pattern: write to temp file, then rename
-	temporaryPath := r.path + ".tmp"
+	temporaryPath := registry.path + ".tmp"
 	if err := os.WriteFile(temporaryPath, data, 0644); err != nil {
 		return fmt.Errorf("failed to write peers temp file: %w", err)
 	}
 
-	if err := os.Rename(temporaryPath, r.path); err != nil {
+	if err := os.Rename(temporaryPath, registry.path); err != nil {
 		os.Remove(temporaryPath) // Clean up temp file
 		return fmt.Errorf("failed to rename peers file: %w", err)
 	}
@@ -660,41 +660,41 @@ func (r *PeerRegistry) saveNow() error {
 }
 
 // defer registry.Close() // flush pending writes on shutdown
-func (r *PeerRegistry) Close() error {
-	r.saveStopOnce.Do(func() {
-		close(r.stopChan)
+func (registry *PeerRegistry) Close() error {
+	registry.saveStopOnce.Do(func() {
+		close(registry.stopChan)
 	})
 
 	// Cancel pending timer and save immediately if dirty
-	r.saveMutex.Lock()
-	if r.saveTimer != nil {
-		r.saveTimer.Stop()
-		r.saveTimer = nil
+	registry.saveMutex.Lock()
+	if registry.saveTimer != nil {
+		registry.saveTimer.Stop()
+		registry.saveTimer = nil
 	}
-	shouldSave := r.dirty
-	r.dirty = false
-	r.saveMutex.Unlock()
+	shouldSave := registry.dirty
+	registry.dirty = false
+	registry.saveMutex.Unlock()
 
 	if shouldSave {
-		r.mutex.RLock()
-		err := r.saveNow()
-		r.mutex.RUnlock()
+		registry.mutex.RLock()
+		err := registry.saveNow()
+		registry.mutex.RUnlock()
 		return err
 	}
 
 	return nil
 }
 
-// r.save() // schedules a debounced write; errors logged asynchronously
-// Must NOT be called with r.mutex held.
-func (r *PeerRegistry) save() error {
-	r.scheduleSave()
+// registry.save() // schedules a debounced write; errors logged asynchronously
+// Must NOT be called with registry.mutex held.
+func (registry *PeerRegistry) save() error {
+	registry.scheduleSave()
 	return nil // Errors will be logged asynchronously
 }
 
-// if err := r.load(); err != nil { /* no existing peers, that's ok */ }
-func (r *PeerRegistry) load() error {
-	data, err := os.ReadFile(r.path)
+// if err := registry.load(); err != nil { /* no existing peers, that's ok */ }
+func (registry *PeerRegistry) load() error {
+	data, err := os.ReadFile(registry.path)
 	if err != nil {
 		return fmt.Errorf("failed to read peers: %w", err)
 	}
@@ -704,9 +704,9 @@ func (r *PeerRegistry) load() error {
 		return fmt.Errorf("failed to unmarshal peers: %w", err)
 	}
 
-	r.peers = make(map[string]*Peer)
+	registry.peers = make(map[string]*Peer)
 	for _, peer := range peers {
-		r.peers[peer.ID] = peer
+		registry.peers[peer.ID] = peer
 	}
 
 	return nil