Mitigates the high-volume render throughput regression via Debenu document
batching + merge (100k-record benchmark: 315s, ~47.5% under the 10-minute
target), delivers the first CSV field-mapping slice (load headers, bind and
rebind dynamic fields), and closes out Sprint 3 with review and retrospective
notes. Also refines and sizes two new backlog stories for text/field element
rotation, requested mid-sprint.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Sprint Review (product-owner): verified all 5 committed stories against
acceptance criteria (goal met, two tracked caveats), updated the backlog
with verification notes and two new follow-up stories, and flagged a
process-improvement item.

Sprint Retrospective (scrum-master): named team-level strengths to keep
(dependency-ordered batch swarming; leave-it-better-than-you-found-it
and honest gap reporting), checked for anti-patterns (none found beyond
one named near-miss), and proposed a Definition of Done edit requiring
verification against the actual built artifact for any story that
changes launch/packaging/config-resolution behavior — directly
addressing how the license-key bug reached "Done" undetected.

User approved the proposed edit; applied to
templates/definition_of_done.md and marked Applied in
logs/process_improvement_log.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>