Self-connection block bypassed when embedding smokescreen with a custom listener on a non-Config.Port port

[graysoncooper]

addrIsLocalIp only treats an address as local when its port equals Config.Port:

smokescreen/pkg/smokescreen/smokescreen.go

Lines 291 to 292 in f03c477

	func addrIsLocalIp(config *Config, addr *net.TCPAddr) bool {
	if addr.Port == int(config.Port) {

When smokescreen is started with a caller-supplied listener, StartWithConfig assigns config.Listener directly and never reads listener.Addr() or updates Config.Port:

smokescreen/pkg/smokescreen/smokescreen.go

Lines 1054 to 1057 in f03c477

	listener := config.Listener
	if listener == nil {
	listener, err = findListener(config.Ip, config.Port)

Effect
If the supplied listener binds a different port than Config.Port (e.g. Config.Port 4750, listener on 4751), a CONNECT to the proxy's own address on the real listener port is not classified as a self-connection. For an allowed local range this can let the proxy dial itself, enabling recursive proxying and resource exhaustion.

Reproduction

1. Build a Config with Port=4750 and LocalIPs containing 127.0.0.1.
2. Provide Config.Listener bound to 127.0.0.1:4751 and start the proxy.
3. Send CONNECT through the proxy to 127.0.0.1:4751 and compare with :4750.

Scope
Reachable via the embedded API when a custom listener binds a port other than Config.Port; the standard CLI path (which derives the listener from Config.Port) is not affected.

Suggested fix
When a listener is supplied, set Config.Port from listener.Addr() before initializing self-connection detection, or compare against the listener's actual port in addrIsLocalIp.

Found while testing Ito, an automated code-review tool, against recently-merged PRs. It's free for open source. Sharing this because it looked like a real bug worth fixing, not to sell anything: https://app.ito.ai/share/0c0a8532-eeb3-4d6a-9a6e-77b451783f5b?tab=details