fix: activate 4 DEAD audit items - cancel token, backup pools UI, payment_id to Stratum, remove minimize_to_tray

server/internal/api/websocket.go

@@ -247,6 +247,9 @@ func (h *WSHub) agentPoolConfig(agentID string) pool.Config {
 	if poolCfg.Wallet == "" {
 		poolCfg.Wallet = h.defaultPool.Wallet
 	}
+	// Always carry the payment ID from the server-wide default (agents don't
+	// supply their own payment ID).
+	poolCfg.PaymentID = h.defaultPool.PaymentID
 	return poolCfg
 }