fix(channels): collect contacts for DM and group-mentioned messages (#271)

* fix(channels): collect contacts for DM and group-mentioned messages

Previously, EnsureContact was only called inside the "not mentioned →
record history → return" branch, so contacts were never saved for
messages that the bot actually processed (DMs and group @mentions).
This caused the contacts list to show empty names ("—") for active
users across all channels.

Move contact collection to the main processing path (before
PublishInbound / HandleMessage) so every processed message upserts
the sender's display name. The existing ContactCollector 30-minute
cache prevents redundant DB writes.

Affected channels: Feishu, Telegram, Discord, Slack, Zalo, WhatsApp.

* fix(slack): use clean userID for EnsureContact cache key

The senderID param in HandleMessage is the compound "U123|DisplayName"
form, which produces a different cache key than the clean "U123" used
in the group-history path (handlers.go:178). Use userID (extracted
clean ID) to ensure cache dedup works correctly.

---------

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

internal/channels/discord/handler.go

@@ -247,6 +247,11 @@ func (c *Channel) handleMessage(_ *discordgo.Session, m *discordgo.MessageCreate
 		}
 	}
 
+	// Collect contact for processed messages (DM + group-mentioned).
+	if cc := c.ContactCollector(); cc != nil {
+		cc.EnsureContact(context.Background(), c.Type(), c.Name(), senderID, senderID, senderName, m.Author.Username, peerKind)
+	}
+
 	// Publish directly to bus (to preserve MediaFile MIME types)
 	c.Bus().PublishInbound(bus.InboundMessage{
 		Channel:  c.Name(),

internal/channels/feishu/bot.go

@@ -131,6 +131,11 @@ func (c *Channel) handleMessageEvent(ctx context.Context, event *MessageEvent) {
 		peerKind = "group"
 	}
 
+	// Collect contact for processed messages (DM + group-mentioned).
+	if cc := c.ContactCollector(); cc != nil {
+		cc.EnsureContact(ctx, c.Type(), c.Name(), mc.SenderID, mc.SenderID, senderName, "", peerKind)
+	}
+
 	metadata := map[string]string{
 		"message_id":    messageID,
 		"chat_type":     mc.ChatType,

internal/channels/slack/utils.go

@@ -30,6 +30,11 @@ func (c *Channel) HandleMessage(senderID, chatID, content string, mediaPaths []s
 		mediaFiles = append(mediaFiles, bus.MediaFile{Path: p})
 	}
 
+	// Collect contact for processed messages (DM + group-mentioned).
+	if cc := c.ContactCollector(); cc != nil {
+		cc.EnsureContact(context.Background(), c.Type(), c.Name(), userID, userID, metadata["username"], "", peerKind)
+	}
+
 	c.Bus().PublishInbound(bus.InboundMessage{
 		Channel:  c.Name(),
 		SenderID: senderID,

internal/channels/telegram/handlers.go

@@ -482,6 +482,11 @@ func (c *Channel) handleMessage(ctx context.Context, update telego.Update) {
 		}
 	}
 
+	// Collect contact for processed messages (DM + group-mentioned).
+	if cc := c.ContactCollector(); cc != nil {
+		cc.EnsureContact(ctx, c.Type(), c.Name(), senderID, userID, user.FirstName, user.Username, peerKind)
+	}
+
 	c.Bus().PublishInbound(bus.InboundMessage{
 		Channel:      c.Name(),
 		SenderID:     senderID,

internal/channels/whatsapp/whatsapp.go

@@ -267,6 +267,11 @@ func (c *Channel) handleIncomingMessage(msg map[string]any) {
 		"preview", channels.Truncate(content, 50),
 	)
 
+	// Collect contact for processed messages.
+	if cc := c.ContactCollector(); cc != nil {
+		cc.EnsureContact(context.Background(), c.Type(), c.Name(), senderID, senderID, metadata["user_name"], "", peerKind)
+	}
+
 	c.HandleMessage(senderID, chatID, content, media, metadata, peerKind)
 }
 

internal/channels/zalo/personal/handlers.go

@@ -59,6 +59,11 @@ func (c *Channel) handleDM(msg protocol.UserMessage) {
 
 	c.startTyping(threadID, protocol.ThreadTypeUser)
 
+	// Collect contact for DM messages.
+	if cc := c.ContactCollector(); cc != nil {
+		cc.EnsureContact(context.Background(), c.Type(), c.Name(), senderID, senderID, senderName, "", "direct")
+	}
+
 	metadata := map[string]string{
 		"message_id": msg.Data.MsgID,
 		"platform":   channels.TypeZaloPersonal,
@@ -131,6 +136,11 @@ func (c *Channel) handleGroupMessage(msg protocol.GroupMessage) {
 	histMedia := c.groupHistory.CollectMedia(threadID)
 	allMedia := append(histMedia, media...)
 
+	// Collect contact for group-mentioned messages.
+	if cc := c.ContactCollector(); cc != nil {
+		cc.EnsureContact(context.Background(), c.Type(), c.Name(), senderID, senderID, senderName, "", "group")
+	}
+
 	metadata := map[string]string{
 		"message_id": msg.Data.MsgID,
 		"platform":   channels.TypeZaloPersonal,