Agent Skills: handoff

Write or refresh a HANDOFF-<slug>.md briefing in the root of the working directory that transfers everything this session knows, so the next agent continues the work as this agent would - from that file alone, with no transcript and no re-explaining. Use when the user asks to hand off or save the session or to write down where things stand, when context is running low, at the end of a work stint, or before a long or risky operation that could end the session.