docs: update iteration log with PR link

Author: algonormative

docs/design/iterations/2026-01-23-005.md

@@ -5,8 +5,8 @@ status: success
 started_at: 2026-01-23T18:28:00Z
 completed_at: 2026-01-23T18:45:00Z
 branch: feature/iterate-2026-01-23-005
-commit: 532ed16
-pr: TBD
+commit: df2cf80
+pr: https://github.com/chronick/duopulse/pull/28
 estimate_accuracy: 95
 ---