fix: update error handling in Start methods for netlink, nfqueue, redirect, and tproxy servers to indicate Linux support only

src/internal/server/netlink/netlink_others.go

@@ -3,6 +3,8 @@
 package netlink
 
 import (
+	"errors"
+
 	"github.com/sunbk201/ua3f/internal/config"
 )
 
@@ -22,7 +24,7 @@ func (s *Server) Setup() (err error) {
 }
 
 func (s *Server) Start() (err error) {
-	return nil
+	return errors.New("netlink helper is only supported on linux")
 }
 
 func (s *Server) Close() (err error) {

src/internal/server/nfqueue/nfqueue_others.go

@@ -3,6 +3,8 @@
 package nfqueue
 
 import (
+	"errors"
+
 	"github.com/sunbk201/ua3f/internal/config"
 	"github.com/sunbk201/ua3f/internal/rewrite"
 )
@@ -25,7 +27,7 @@ func (s *Server) Setup() (err error) {
 }
 
 func (s *Server) Start() (err error) {
-	return nil
+	return errors.New("nfqueue server is only supported on linux")
 }
 
 func (s *Server) Close() (err error) {

src/internal/server/redirect/redirect_others.go

@@ -3,7 +3,7 @@
 package redirect
 
 import (
-	"fmt"
+	"errors"
 	"net"
 
 	"github.com/sunbk201/ua3f/internal/config"
@@ -24,7 +24,7 @@ func New(cfg *config.Config, rw *rewrite.Rewriter) *Server {
 }
 
 func (s *Server) Start() error {
-	return fmt.Errorf("REDIRECT Mode is only supported on Linux")
+	return errors.New("redirect server is only supported on linux")
 }
 
 func (s *Server) Close() error {

src/internal/server/tproxy/tproxy_others.go

@@ -3,7 +3,7 @@
 package tproxy
 
 import (
-	"fmt"
+	"errors"
 	"net"
 
 	"github.com/sunbk201/ua3f/internal/config"
@@ -24,7 +24,7 @@ func New(cfg *config.Config, rw *rewrite.Rewriter) *Server {
 }
 
 func (s *Server) Start() error {
-	return fmt.Errorf("TPROXY Mode is only supported on Linux")
+	return errors.New("tproxy server is only supported on linux")
 }
 
 func (s *Server) Close() error {