fix(feishu): gate group pairing by target bot (#1291)

* fix(feishu): require exact bot_open_id match for mention detection

- Previously, when bot_open_id was empty, ALL mentions were treated as bot mentions
- This caused multiple agents in same group to all respond to any mention
- Now requires bot_open_id to be set AND match exactly for mentionedBot=true
- Fixes issue where CPPAI PM would respond even when other agent was mentioned

* fix(feishu): gate group pairing by target bot

---------

Co-authored-by: ntduc <ntduc@cpp.ai.vn>

internal/channels/feishu/bot_parse.go

@@ -31,16 +31,18 @@ func (c *Channel) parseMessageEvent(event *MessageEvent) *messageContext {
 	mentionedBot := false
 	for _, m := range msg.Mentions {
 		mi := mentionInfo{
-			Key:    m.Key,
-			OpenID: m.ID.OpenID,
-			Name:   m.Name,
+			Key:       m.Key,
+			OpenID:    m.ID.OpenID,
+			UserID:    m.ID.UserID,
+			UnionID:   m.ID.UnionID,
+			Name:      m.Name,
+			TenantKey: m.TenantKey,
 		}
 		mentions = append(mentions, mi)
 
-		// Check if bot is mentioned.
-		// If botOpenID is known, match exactly; otherwise treat any mention as bot mention
-		// (fallback when probeBotInfo fails — better to process than silently drop).
-		if c.botOpenID == "" || mi.OpenID == c.botOpenID {
+		// Check if this bot is mentioned. Unknown bot identity must fail closed
+		// so multi-agent groups do not all respond to another bot's mention.
+		if c.botOpenID != "" && mi.OpenID == c.botOpenID {
 			mentionedBot = true
 		}
 	}
@@ -252,3 +254,15 @@ func resolveMentions(text string, mentions []mentionInfo, botOpenID string) stri
 	}
 	return strings.TrimSpace(text)
 }
+
+func formatMentionInfos(mentions []mentionInfo) []string {
+	if len(mentions) == 0 {
+		return nil
+	}
+	out := make([]string, 0, len(mentions))
+	for _, m := range mentions {
+		out = append(out, fmt.Sprintf("key=%s open_id=%s user_id=%s union_id=%s name=%s tenant=%s",
+			m.Key, m.OpenID, m.UserID, m.UnionID, m.Name, m.TenantKey))
+	}
+	return out
+}