fix local address population and snmp reverse port discovery

populate root node with local macs/ips at startup, excluding loopback addresses and permanent arp entries. detect when snmp finds parent node mac in child forwarding table and set child localport.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

arp.go

@@ -63,6 +63,11 @@ func (t *Tendrils) parseARPDarwin() []arpEntry {
 	scanner := bufio.NewScanner(strings.NewReader(string(output)))
 	for scanner.Scan() {
 		line := scanner.Text()
+
+		if strings.Contains(line, "permanent") {
+			continue
+		}
+
 		fields := strings.Fields(line)
 		if len(fields) < 6 {
 			continue