refactor(panel): drop two duplicated helpers

SettingService.GetDefaultJSONConfig was a byte-identical copy of
GetDefaultXrayConfig with no callers anywhere in the tree.

amneziawgnet.normalizeDNSServer re-implemented the exported
amneziawg.NormalizeDNSServer line for line, in a file that already imports
that package for EffectiveMTU three lines above it. Its two callers now use
the exported one, so the bare-IP-to-host:port rule has a single definition.

internal/amneziawgnet/dns.go

@@ -14,6 +14,7 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
 
+	"github.com/mhsanaei/3x-ui/v3/internal/amneziawg"
 	"github.com/mhsanaei/3x-ui/v3/internal/logger"
 )
 
@@ -78,7 +79,7 @@ func dnsCacheKey(tag, dnsServer, host string) string {
 }
 
 func resolveTunnelVia(ctx context.Context, dev *Device, tag string, dnsServer string, host string) (netip.Addr, error) {
-	normDNS := normalizeDNSServer(dnsServer)
+	normDNS := amneziawg.NormalizeDNSServer(dnsServer)
 	if normDNS == "" {
 		normDNS = defaultDNSFor(dev.LocalAddresses())
 	}

internal/amneziawgnet/egress.go

@@ -14,6 +14,7 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
 
+	"github.com/mhsanaei/3x-ui/v3/internal/amneziawg"
 	"github.com/mhsanaei/3x-ui/v3/internal/logger"
 )
 
@@ -77,7 +78,7 @@ func (s *socks5EgressServer) SetDNSServer(addr string) {
 func (s *socks5EgressServer) SetStack(tag string, dev *Device, dnsServer ...string) {
 	norm := ""
 	if len(dnsServer) > 0 && dnsServer[0] != "" {
-		norm = normalizeDNSServer(dnsServer[0])
+		norm = amneziawg.NormalizeDNSServer(dnsServer[0])
 	}
 	s.mu.Lock()
 	prevDev := s.stacks[tag]

internal/amneziawgnet/outbound_manager.go

@@ -2,7 +2,6 @@ package amneziawgnet
 
 import (
 	"fmt"
-	"net/netip"
 	"strings"
 	"sync"
 
@@ -53,21 +52,6 @@ func outboundFingerprint(inst amneziawg.OutboundInstance) string {
 		strings.Join(inst.Address, ","))
 }
 
-// normalizeDNSServer normalizes a configured DNS server to host:port.
-func normalizeDNSServer(s string) string {
-	s = strings.TrimSpace(s)
-	if s == "" {
-		return ""
-	}
-	if addr, err := netip.ParseAddr(s); err == nil {
-		return netip.AddrPortFrom(addr, 53).String()
-	}
-	if ap, err := netip.ParseAddrPort(s); err == nil {
-		return ap.String()
-	}
-	return s
-}
-
 // Reconcile converges devices to desired and stops removed tags; per-tick
 // contract of Manager.Reconcile -- errors log, never abort the batch.
 func (m *OutboundManager) Reconcile(desired []OutboundDesired) {

internal/web/service/setting.go

@@ -209,15 +209,6 @@ var defaultValueMap = map[string]string{
 // It handles configuration storage, retrieval, and validation for all system settings.
 type SettingService struct{}
 
-func (s *SettingService) GetDefaultJSONConfig() (any, error) {
-	var jsonData any
-	err := json.Unmarshal([]byte(xrayTemplateConfig), &jsonData)
-	if err != nil {
-		return nil, err
-	}
-	return jsonData, nil
-}
-
 func (s *SettingService) GetAllSetting() (*entity.AllSetting, error) {
 	db := database.GetDB()
 	settings := make([]*model.Setting, 0)