Fix IPv6 TCP tunnel display formatting (#1980)

Normalize composite tunnel display values before rendering peer and
debug output so IPv6 tunnel types no longer append `6` to the port.

- Preserve prefixes like `txt-` while converting tunnel schemes to
  their IPv6 form.
- Recover malformed values such as `txt-tcp://...:110106` into
  `txt-tcp6://...:11010`.
- Reuse the normalized remote address display in CLI debug output.

easytier/src/tunnel/udp.rs

@@ -428,6 +428,9 @@ impl UdpTunnelListenerData {
                 remote_addr: Some(
                     build_url_from_socket_addr(&remote_addr.to_string(), "udp").into(),
                 ),
+                resolved_remote_addr: Some(
+                    build_url_from_socket_addr(&remote_addr.to_string(), "udp").into(),
+                ),
             }),
         ));
 
@@ -772,6 +775,9 @@ impl UdpTunnelConnector {
                     build_url_from_socket_addr(&socket.local_addr()?.to_string(), "udp").into(),
                 ),
                 remote_addr: Some(self.addr.clone().into()),
+                resolved_remote_addr: Some(
+                    build_url_from_socket_addr(&dst_addr.to_string(), "udp").into(),
+                ),
             }),
         )))
     }