Replace the single-sender containsExactlyInAnyOrder check with a two-sender fixture and ordered containsExactly proving an undated doc stays within its sender group and never floats to the page head. Add a DESC-direction case for in-memory-path symmetry and an undated=true + sort=SENDER case capturing the Specification to prove undatedOnly is still applied on the person-sort path. Refs #668 Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>