docs: require cleanup before completion

.config/opencode/AGENTS.md

@@ -40,6 +40,7 @@
 - A "meaningful checkpoint" is a completed implementation chunk from the approved plan, not every file save.
 - Skip commit creation when there are no new changes since the prior checkpoint.
 - Commit messages should reflect the intent of the completed task from the plan.
+- Before creating the final completion commit, clean up temporary artifacts generated during the build (e.g., scratch files, screenshots, logs, transient reports, caches). Intended committed deliverables are not cleanup targets.
 - Standard git safety rules apply: review staged content, respect hooks, no force-push or destructive operations.
 - Push automation is out of scope; the user decides when to push.