Function gatherCompactionInput

pkg/runtime/compactor/compactor.go:264–271

gatherCompactionInput is a thin wrapper around [session.Session.CompactionInput] that clears compaction-specific fields on the returned chat messages. Cost is per-message bookkeeping already accumulated into sess.TotalCost(); leaving it set would double-count when the summarization session reports

(sess *session.Session)

// — lives on Session itself so it can run under sess.mu.RLock and stay
// race-safe against concurrent AddMessage / ApplyCompaction calls.
func gatherCompactionInput(sess *session.Session) ([]chat.Message, []int) {
	messages, sessIndices := sess.CompactionInput()
	for i := range messages {
		messages[i].Cost = 0
		messages[i].CacheControl = false
	}
	return messages, sessIndices
}

// extractMessages returns the messages to send to the compaction
// model, plus the index (into sess.Messages) of the first message