- Stop deleting imm_daily_rollups/imm_monthly_rollups on unrelated schema version bumps; their source session/telemetry rows may already be pruned, so deleted buckets could not be rebuilt
- Run startup session-rollup maintenance before the lexical rollup backfill takes the write lock, so recovery no longer races playback writes
- Update the vocabulary summary totals changelog fragment to reflect that watch-time, activity, efficiency, and library charts are no longer cleared during rebuilds
sudacode