Dokodemo-door: Add simple tunnel config (alias and default values) (#4968)

dokodemo-door -> tunnel
freedom -> direct
blackhole -> block

https://github.com/XTLS/Xray-core/discussions/4966#discussioncomment-13948546
https://github.com/XTLS/Xray-core/pull/4967#issuecomment-3143951306

proxy/dokodemo/dokodemo.go

@@ -3,6 +3,8 @@ package dokodemo
 import (
 	"context"
 	"runtime"
+	"strconv"
+	"strings"
 	"sync/atomic"
 
 	"github.com/xtls/xray-core/common"
@@ -73,6 +75,25 @@ func (d *DokodemoDoor) Process(ctx context.Context, network net.Network, conn st
 		Port:    d.port,
 	}
 
+	if !d.config.FollowRedirect {
+		host, port, err := net.SplitHostPort(conn.LocalAddr().String())
+		if dest.Address == nil {
+			if err != nil {
+				dest.Address = net.DomainAddress("localhost")
+			} else {
+				if strings.Contains(host, ".") {
+					dest.Address = net.LocalHostIP
+				} else {
+					dest.Address = net.LocalHostIPv6
+				}
+			}
+		}
+		if dest.Port == 0 {
+			dest.Port = net.Port(common.Must2(strconv.Atoi(port)).(int))
+		}
+
+	}
+
 	destinationOverridden := false
 	if d.config.FollowRedirect {
 		outbounds := session.OutboundsFromContext(ctx)