Session handoff

Write a handoff document that lets a fresh agent continue the work without re-deriving it. Save it outside the repo — the OS temp directory — unless the user names a location; a handoff is session plumbing, not a project artifact.

What goes in

• Goal — what the overall task is and what "done" means.
• Current state — what is finished and verified, what is in flight, what is untouched.
• Decisions and why — choices made during the session that the next agent must not silently re-litigate.
• Next steps — concrete, ordered, starting with the very next action.
• Gotchas — dead ends already explored, flaky commands, environment quirks, things that look wrong but are deliberate.
• Suggested skills — which skills the next agent should invoke and at which step.

If the user says what the next session will focus on, weight the document toward that.

Reference, don't duplicate

Content already captured in artifacts — PRDs, plans, ADRs, specs, issues, commits, diffs — is referenced by path or URL, never pasted. The handoff carries what exists only in the conversation.