Support IPv6 for the embedded VNC server and browser proxy

client/wasm/internal/netutil/network.go

@@ -0,0 +1,16 @@
+// Package netutil holds small networking helpers shared across the wasm
+// client's proxy paths (SSH, VNC, ping).
+package netutil
+
+// TCPNetwork maps an IP-version selector to the net package's TCP network
+// string: 4 -> "tcp4", 6 -> "tcp6", anything else (0/automatic) -> "tcp".
+func TCPNetwork(ipVersion int) string {
+	switch ipVersion {
+	case 4:
+		return "tcp4"
+	case 6:
+		return "tcp6"
+	default:
+		return "tcp"
+	}
+}