Add Feishu channel adapter with webhook and send path

config/default.yaml

@@ -62,6 +62,16 @@ telegram:
 #   require_mention: true
 #   mention_name: flynn
 
+# Optional: Feishu / Lark
+# feishu:
+#   app_id: ${FEISHU_APP_ID}
+#   app_secret: ${FEISHU_APP_SECRET}
+#   webhook_token: ${FEISHU_WEBHOOK_TOKEN}
+#   allowed_chat_ids: []             # Empty = allow all chats
+#   require_mention: true
+#   mention_name: flynn
+#   endpoint: https://open.feishu.cn
+
 server:
   # Tailscale Serve config (optional). Enable `serve: true` to expose the
   # gateway to your tailnet via `tailscale serve`.