Add the schema for the summarization-mode feature: a per-user auto/manual
toggle (users.auto_summarize, default FALSE = manual) and a per-video manual
queue flag (videos.summarize_requested, default FALSE).
Both columns land on tables that already have ENABLE + FORCE ROW LEVEL
SECURITY (migration 003), so they inherit per-user isolation automatically —
no policy changes needed. auto_summarize is per-user, not global, per ADR-012.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
