fix: harden channel retry attribution and operations UI

gateway/internal/upstream/manager.go

@@ -1284,6 +1284,7 @@ func submitResult(cmd queue.SubmitCommand, sequenceID uint32, gatewayMessageID s
 			ChannelID:     cmd.ChannelID,
 			CreatedAt:     time.Now().UTC(),
 		},
+		SubmitID:         cmd.SubmitID,
 		SequenceID:       sequenceID,
 		GatewayMessageID: gatewayMessageID,
 		SubmitStatus:     status,

gateway/internal/upstream/submit_packet_test.go

@@ -41,6 +41,20 @@ func TestSubmitRequestPacketUsesCMPP2PacketForCMPP20Channel(t *testing.T) {
 	}
 }
 
+func TestSubmitResultKeepsCommandSubmitID(t *testing.T) {
+	cmd := submitCommandForPacketTest("2.0")
+	cmd.SubmitID = "submit-attempt-2"
+
+	result := submitResult(cmd, 42, "9001", "accepted", "", "")
+
+	if result.SubmitID != cmd.SubmitID {
+		t.Fatalf("SubmitID = %q, want %q", result.SubmitID, cmd.SubmitID)
+	}
+	if result.ChannelID != cmd.ChannelID || result.MessageID != cmd.MessageID {
+		t.Fatalf("unexpected result envelope: %+v", result.Envelope)
+	}
+}
+
 func TestSubmitRequestPacketUsesCMPP3PacketForCMPP30Channel(t *testing.T) {
 	conn := &connection{config: queue.UpstreamConfig{CMPPVersion: "3.0", Account: "ljcs02"}}
 	cmd := submitCommandForPacketTest("3.0")