fix(matcher,server): use ConflictError in AddNamed and add tests

Make AddNamed return *ConflictError for consistency with other Add*
methods so handleRegistrationError treats named location conflicts as
warnings instead of fatal errors. Add tests for handleRegistrationError
covering both conflict and fatal error paths.

internal/matcher/location.go

@@ -173,8 +173,12 @@ func (e *LocationEngine) AddNamed(name string, handler fasthttp.RequestHandler)
 		return errors.New("LocationEngine already initialized")
 	}
 
-	if existing, ok := e.namedMatchers[name]; ok {
-		return fmt.Errorf("named location '@%s' already registered", existing.name)
+	if _, ok := e.namedMatchers[name]; ok {
+		return &ConflictError{
+			Path:         "@" + name,
+			ExistingType: "named",
+			NewType:      "named",
+		}
 	}
 
 	matcher := NewNamedMatcher(name, handler)

internal/server/server_test.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -26,6 +27,7 @@ import (
 	"rua.plus/lolly/internal/config"
 	"rua.plus/lolly/internal/loadbalance"
 	"rua.plus/lolly/internal/lua"
+	"rua.plus/lolly/internal/matcher"
 	"rua.plus/lolly/internal/middleware/accesslog"
 	"rua.plus/lolly/internal/middleware/security"
 	"rua.plus/lolly/internal/proxy"
@@ -989,6 +991,27 @@ func TestCreateListener_UnixSocketCleanup(t *testing.T) {
 	defer ln.Close()
 }
 
+func TestHandleRegistrationError_ConflictWarning(t *testing.T) {
+	s := &Server{}
+	err := s.handleRegistrationError("proxy", "/api",
+		&matcher.ConflictError{Path: "/api", ExistingType: "exact", NewType: "prefix"})
+	if err != nil {
+		t.Errorf("conflict should return nil, got: %v", err)
+	}
+}
+
+func TestHandleRegistrationError_FatalError(t *testing.T) {
+	s := &Server{}
+	err := s.handleRegistrationError("proxy", "/api",
+		fmt.Errorf("invalid regex pattern: missing closing parenthesis"))
+	if err == nil {
+		t.Error("fatal error should return non-nil")
+	}
+	if !strings.Contains(err.Error(), "proxy route /api") {
+		t.Errorf("error should wrap context, got: %v", err)
+	}
+}
+
 func TestDupListener_TCP(t *testing.T) {
 	ln, err := net.Listen("tcp", "127.0.0.1:0")
 	if err != nil {