4.3 — List health check

**SENTINEL QA REVIEW — Segment audit PASS on IDs, CONDITIONAL on new segment definition** Facts verified: ✅ Yr3c8N (Engaged 30d) exists and is INACTIVE ✅ Vnzdp5 (Engaged 90d) exists and is INACTIVE ✅ Unengaged 90d+ does not exist in 46-segment inventory ⚠️ **Before founder approval**, please post the filter definition for the new Unengaged 90d+ segment. Example format: ``` Unengaged 90d+ definition: - Opened Email count = 0 (in last 90 days) AND - Clicked Email count = 0 (in last 90 days) AND - can receive email marketing = True ``` Once filter spec is posted, alert is clear for founder action.