Prefer capacity/openresty rollups only when they cover the 24h window;
otherwise merge per hour so raw fills pre-MV gaps and rollup wins on
overlap. Add a one-time ANTI JOIN backfill migration for the last 30 days.
Materialized capacity/openresty hourly tables only hold data after the MV
exists. Preferring any non-empty rollup hid full raw history and left 24h
charts with only recent hours. Use rollup only when its earliest bucket
covers the query window start.