fix(channels): add display_name to session metadata for Feishu, Zalo, Slack (#536)

Sessions page shows raw IDs instead of sender names because these channels
didn't include display_name in their message metadata. The gateway's
extractSessionMetadata() already looks for this key but it was missing
from Feishu, Zalo Personal, and Slack message payloads.

Co-authored-by: Luvu182 <208665161+Luvu182@users.noreply.github.com>

internal/channels/feishu/bot.go

@@ -169,6 +169,7 @@ func (c *Channel) handleMessageEvent(ctx context.Context, event *MessageEvent) {
 		"message_id":    messageID,
 		"chat_type":     mc.ChatType,
 		"sender_name":   senderName,
+		"display_name":  senderName,
 		"mentioned_bot": fmt.Sprintf("%t", mc.MentionedBot),
 		"platform":      channels.TypeFeishu,
 	}

internal/channels/slack/handlers.go

@@ -253,6 +253,7 @@ func (c *Channel) handleMessage(ev *slackevents.MessageEvent) {
 		"message_id":      ev.TimeStamp,
 		"user_id":         senderID,
 		"username":        displayName,
+		"display_name":    displayName,
 		"channel_id":      channelID,
 		"is_dm":           fmt.Sprintf("%t", isDM),
 		"local_key":       localKey,

internal/channels/zalo/personal/handlers.go

@@ -68,8 +68,9 @@ func (c *Channel) handleDM(msg protocol.UserMessage) {
 	}
 
 	metadata := map[string]string{
-		"message_id": msg.Data.MsgID,
-		"platform":   channels.TypeZaloPersonal,
+		"message_id":   msg.Data.MsgID,
+		"platform":     channels.TypeZaloPersonal,
+		"display_name": senderName,
 	}
 	c.HandleMessage(senderID, threadID, content, media, metadata, "direct")
 }
@@ -147,9 +148,10 @@ func (c *Channel) handleGroupMessage(msg protocol.GroupMessage) {
 	}
 
 	metadata := map[string]string{
-		"message_id": msg.Data.MsgID,
-		"platform":   channels.TypeZaloPersonal,
-		"group_id":   threadID,
+		"message_id":   msg.Data.MsgID,
+		"platform":     channels.TypeZaloPersonal,
+		"group_id":     threadID,
+		"display_name": senderName,
 	}
 	c.HandleMessage(senderID, threadID, finalContent, allMedia, metadata, "group")