Fix Telegram inbound reply threading

pkg/agent/loop.go

@@ -1577,6 +1577,8 @@ func (al *AgentLoop) processSystemMessage(
 		UserMessage:     fmt.Sprintf("[System: %s] %s", msg.SenderID, msg.Content),
 		DefaultResponse: "Background task completed.",
 		EnableSummary:   false,
+		// System messages are synthetic inbound events, so there is no delivery
+		// callback chain from a channel send to feed assistant message IDs back.
 		SendResponse: true,
 	})
 }

pkg/channels/telegram/telegram.go

@@ -708,6 +708,9 @@ func (c *TelegramChannel) handleMessage(ctx context.Context, message *telego.Mes
 		"first_name": user.FirstName,
 		"is_group":   fmt.Sprintf("%t", message.Chat.Type != "private"),
 	}
+	if message.ReplyToMessage != nil {
+		metadata["reply_to_message_id"] = fmt.Sprintf("%d", message.ReplyToMessage.MessageID)
+	}
 
 	// Set parent_peer metadata for per-topic agent binding.
 	if message.Chat.IsForum && threadID != 0 {

pkg/channels/telegram/telegram_test.go

@@ -686,6 +686,21 @@ func TestHandleMessage_EmptyContent_Ignored(t *testing.T) {
 		From: &telego.User{
 			ID:        789,
 			FirstName: "User",
+=======
+	msg := &telego.Message{
+		Text:      "reply in group",
+		MessageID: 30,
+		Chat: telego.Chat{
+			ID:   -100999,
+			Type: "supergroup",
+		},
+		From: &telego.User{
+			ID:        10,
+			FirstName: "Dana",
+		},
+		ReplyToMessage: &telego.Message{
+			MessageID: 25,
+>>>>>>> 7b6328f (Fix Telegram inbound reply threading)
 		},
 	}
 
@@ -699,3 +714,37 @@ func TestHandleMessage_EmptyContent_Ignored(t *testing.T) {
 	default:
 	}
 }
+
+func TestHandleMessage_ReplyToMessageID_Preserved(t *testing.T) {
+	messageBus := bus.NewMessageBus()
+	ch := &TelegramChannel{
+		BaseChannel: channels.NewBaseChannel("telegram", nil, messageBus, nil),
+		chatIDs:     make(map[string]int64),
+		ctx:         context.Background(),
+	}
+
+	msg := &telego.Message{
+		Text:      "reply in group",
+		MessageID: 30,
+		Chat: telego.Chat{
+			ID:   -100999,
+			Type: "supergroup",
+		},
+		From: &telego.User{
+			ID:        10,
+			FirstName: "Dana",
+		},
+		ReplyToMessage: &telego.Message{
+			MessageID: 25,
+		},
+	}
+
+	err := ch.handleMessage(context.Background(), msg)
+	require.NoError(t, err)
+
+	inbound, ok := <-messageBus.InboundChan()
+	require.True(t, ok)
+	assert.Equal(t, "30", inbound.MessageID)
+	assert.Equal(t, "25", inbound.ReplyToMessageID)
+	assert.Equal(t, "25", inbound.Metadata["reply_to_message_id"])
+}