feat(channels): share line and zalo binary attachments via minio

README.md

@@ -214,6 +214,8 @@ line:
   allowed_source_ids: []   # Empty = allow all users/groups/rooms
   require_mention: true
   mention_name: "flynn"
+# Binary attachments: when backup.minio.enabled is configured, Flynn uploads
+# LINE binary attachments to MinIO and sends a share URL automatically.
 
 # LINE webhook endpoint should point to:
 # POST https://<your-flynn-host>/line/events
@@ -239,6 +241,8 @@ zalo:
   require_mention: true
   mention_name: "flynn"
   endpoint: "https://openapi.zalo.me"
+# Binary attachments: when backup.minio.enabled is configured, Flynn uploads
+# Zalo binary attachments to MinIO and sends a share URL automatically.
 
 # Zalo webhook endpoint should point to:
 # POST https://<your-flynn-host>/zalo/events