How do I prevent long chats from becoming slow?

Long chats slow down because old drafts, discarded ideas and file excerpts stay in the working context. The issue is rarely one message; it is too much history competing with the current task.

Create a short Scratch handover with goal, valid decisions, relevant files, open questions and points that no longer apply. Start the next chat in the same space from that handover.

After the restart, check whether the answer follows only the current summary. If outdated assumptions return, the handover needs a clearer exclusion list.