feat: multi-node device limit, optimize rate limiter

internal/kernel/xray/dispatcher.go

@@ -159,7 +159,7 @@ func (d *LimitDispatcher) identifyAndCheck(ctx context.Context, dest net.Destina
 	isTCP = dest.Network == net.Network_TCP
 
 	if d.checkDeviceLimit(email, sourceIP, isTCP) {
-		nlog.Core().Info("xray: device limit exceeded", "email", email, "ip", sourceIP)
+		nlog.Core().Debug("xray: device limit exceeded", "email", email, "ip", sourceIP)
 		return "", "", false, errors.New("device limit exceeded for " + email)
 	}
 	return email, sourceIP, isTCP, nil

internal/kernel/xray/xray.go

@@ -244,6 +244,12 @@ func (x *Xray) SetSpeedLimitFunc(_ func(string) *rate.Limiter) {}
 // gate-kept by LimitDispatcher.checkDeviceLimit at Dispatch time.
 func (x *Xray) SetDeviceLimitFunc(_ func(string) (int, bool)) {}
 
+// UpdateGlobalDevices is a no-op for xray — xray handles device limits differently.
+func (x *Xray) UpdateGlobalDevices(_ map[int][]string) {}
+
+// ClearGlobalDevices is a no-op for xray.
+func (x *Xray) ClearGlobalDevices() {}
+
 // ─── User management (non-disruptive where possible) ────────────────────────
 
 // AddUsers adds new users to the running kernel via xray's UserManager API.