Agent checkpoint note per task (checkpoint_{timestamp}.md)

[danmaps]

Summary\nAdd a small structured checkpoint note that agents create and commit alongside any generated analysis or automation for a given request/task.\n\nThis is per request/task, not every conversation turn or every code commit.\n\n## Proposal\nWhen an agent completes a task that produces analysis or automation artifacts in the repo, it should write a file in the project folder:\n\n- checkpoint_{timestamp}.md\n\nwith the following structure:\n\n- Intent: what question are we answering\n- Inputs: datasets, layer names, environment assumptions\n- Constraints: accuracy, performance, governance rules\n- Decisions: key forks taken and why (with alternatives considered)\n- Validation: what you checked (counts, spot checks, maps reviewed)\n- Next: what you’d do if this was asked again\n\n## Acceptance Criteria\n- Add to AGENT.md (or equivalent agent guidance doc) a clear instruction to create this checkpoint note per task.\n- Checkpoint format is documented and copy-pastable.\n- Timestamp format documented (recommend ISO-ish, filesystem safe).\n- Clarify that this is for tasks that generate analysis/automation artifacts, not for every commit.\n\n## Notes\n- Consider a dedicated folder (e.g. checkpoints/) if top-level gets noisy, but the default should match whatever keeps discovery easiest.