Channel import crashed on the hard-delete purge path (videos confirmed
gone from YouTube for 30+ days): prisma.video.deleteMany() hit a FK
violation on VideoConfig_videoId_fkey. All four required relations
pointing at Video had no onDelete behavior set, defaulting to RESTRICT
- any of the four would have hit the same crash, not just VideoConfig.
First real channel import against a real, aged dataset is what
surfaced this; nothing had exercised the 30-day hard-delete path before.
