Captures the 6 deviations from the original design (each with driving feedback + commit SHA), the 5 non-design polish commits, and the test delta (42 → 47 passing). Keeps the design doc as the first-read for understanding the feature while preserving decision history from the Checkpoint-1 iteration. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>