Repository: unoplatform/uno
File: src/Uno.UI.RemoteControl/RemoteControlClient.cs (C#)

Code before:
				.Distinct()
				.ToArray();

			if (ports.Length > 0)
			{
				// Create a set of existing endpoints for efficient lookup
				var existingEndpoints = _serverAddresses
					.Select(addr => (addr.endpoint.ToLowerInvariant(), addr.port))
					.ToHashSet();

				var loopbackAddress = IPAddress.Loopback.ToString().ToLowerInvariant();

				// Add loopback addresses with the same ports, but only if not already present
				var loopbackAddresses = ports
					.Select(port => (loopbackAddress, port))
					.Where(loopback => !existingEndpoints.Contains((loopback.loopbackAddress, loopback.port)))
					.ToArray();

				if (loopbackAddresses.Length > 0)
				{
					// Prepend loopback addresses to give them priority
					_serverAddresses = loopbackAddresses.Concat(_serverAddresses).ToArray();
				}
			}
		}

		// Enable hot-reload
		// Note: We register the HR processor even if we _serverAddresses is empty. This is to make sure to create the HR indicator.
		RegisterProcessor(new HotReload.ClientHotReloadProcessor(this));
		_status.RegisterRequiredServerProcessor("Uno.UI.RemoteControl.Host.HotReload.ServerHotReloadProcessor", VersionHelper.GetVersion(typeof(ClientHotReloadProcessor)));

		if (_serverAddresses is null or { Length: 0 })
		{
			if (error is null)
			{
				error = ConnectionError.NoEndpoint;
				this.Log().LogError(
					"Failed to get any valid dev-server endpoint from the IDE."
					+ "Make sure you have the latest version of the uno's extensions installed in your IDE and restart your IDE.");
			}

			_connection = Task.FromResult<Connection?>(null);
			_status.Report(ConnectionState.NoServer, error);
			return;
		}

		_connection = StartConnection();
	}

	public IEnumerable<object> Processors
		=> _processors.Values;

Review comment (suggestion):
@copilot we should add the loopback address only when we read addresses from the `ServerEndpointAttribute`. Please move that in the condition starting on line 241.

Also in order to always have the port number, please update the generator to add the loopback address, but only if there is no other endpoint available. (Add a comment there to explain this is only a fallback for desktop and wasm but it will NOT work for mobile endpoint, that's why we add the loopback only we don't have any other available IP)

Finally, we expect to have only a single port number, just use `ports.FIrstOrDefault()` (do not use SIngle ... even if semantically better, we don't want to safely handle such kind of errors)

Code after:
				}
			}
		}

		if (_serverAddresses is null or { Length: 0 })
		{
			_serverAddresses = endpoints
				?.Select(ep => (ep.Endpoint, ep.Port))
				.ToArray();
		}

		// Enable hot-reload
		// Note: We register the HR processor even if we _serverAddresses is empty. This is to make sure to create the HR indicator.
		RegisterProcessor(new HotReload.ClientHotReloadProcessor(this));
		_status.RegisterRequiredServerProcessor("Uno.UI.RemoteControl.Host.HotReload.ServerHotReloadProcessor", VersionHelper.GetVersion(typeof(ClientHotReloadProcessor)));

		if (_serverAddresses is null or { Length: 0 })
		{
			if (error is null)
			{
				error = ConnectionError.NoEndpoint;
				this.Log().LogError(
					"Failed to get any valid dev-server endpoint from the IDE."
					+ "Make sure you have the latest version of the uno's extensions installed in your IDE and restart your IDE.");
			}

			_connection = Task.FromResult<Connection?>(null);
			_status.Report(ConnectionState.NoServer, error);
			return;
		}

		_connection = StartConnection();
	}

	public IEnumerable<object> Processors
		=> _processors.Values;

	internal IClientProcessor[] RegisteredProcessors
		=> _processors.Values.ToArray();

	internal Task WaitForConnection()
		=> WaitForConnection(CancellationToken.None);

	public Task WaitForConnection(CancellationToken ct)
		=> _connection;

	private void RegisterProcessor(IClientProcessor processor)
		=> _processors[processor.Scope] = processor;

	public void RegisterPreProcessor(IRemoteControlPreProcessor preprocessor)
		=> _preprocessors.Add(preprocessor);