- ReadingMaterialRef → ReadingMaterialRefV2 (full fields, camelCase) - ReadingSessionV2: add closed_at_ms, Interrupted/Failed statuses - EventBuffer: add reload_stale_events_v2, buffer_size_v2 - V1/V2 diff table: add session status/recovery rows - Verification chain: add startup recovery + V2 MaterialRef Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>