Handoff Doc

Write a concise handoff doc that captures the current session's work so a future session can pick up cold. The whole point is leverage: instead of the next session re-reading a long transcript, it reads one tight doc and knows what was done, where things live, what's verified, and what's still open.

The user gives you a destination path. You supply the content by distilling what actually happened in this session. Keep it concise — a handoff is a launch pad, not a transcript.