stripReinjectedAttachments function
Strip attachment types that are re-injected post-compaction anyway.
Skill discovery/listing attachments are re-surfaced on the next turn, so feeding them to the summarizer wastes tokens and pollutes the summary with stale skill suggestions.
Implementation
List<Message> stripReinjectedAttachments(List<Message> messages) {
// In the current Dart model, attachment messages are not a distinct
// type; this is a placeholder for future expansion.
return messages;
}