fix: improve endgame clock and gameplay stability

internal/gameserver/gateway.go

@@ -84,6 +84,7 @@ func (g *Gateway) Listen() error {
 		if n == 20 {
 			if err := g.processNetOperation(append([]byte(nil), buf[:n]...), addr); err != nil {
 				PacketLog("[ERROR] netop: " + err.Error())
+				Log("[KCP] handshake rejected: " + err.Error())
 			}
 		} else if n >= 28 {
 			g.processKCPPayload(append([]byte(nil), buf[:n]...), addr)
@@ -208,6 +209,7 @@ func (g *Gateway) processKCPPayload(data []byte, addr *net.UDPAddr) {
 	// same-conv replays from a stale client get rejected by the token check
 	if err := session.Consume(data); err != nil {
 		PacketLog("[ERROR] Session consume error (" + addr.String() + "): " + err.Error())
+		Log("[KCP] packet rejected: " + err.Error())
 	}
 }