Session Handoff

When you're wrapping up a coding session and know you'll need to pick things up later, this generates a structured handoff document instead of relying on memory or commit messages. It runs git commands to capture your current state, then produces a markdown document with what you finished, what's half done, key decisions you made, and a resume command you can paste into your next session. The distinction it makes is useful: wrap-up is a checklist for you right now, handoff is a document for future you. Saves you from that "wait, what was I doing?" moment when you come back to a branch three days later.