Get Dimension Values

List unique values for a dimension with view counts.

Served from the dimension_values_daily top-K rollup (R4) when the org is backfilled for this dim and the DB is Postgres: sum count per dim_value over the window's UTC days, ORDER BY count DESC, take top-limit. Falls back to the live video_views GROUP BY otherwise (SQLite tests, un-backfilled orgs).

Top-K truncation (cap 200/org/day/dim, see DimensionValuesDaily): a value rare on EVERY day of the window can be absent from the rollup result vs the live query. For the dropdown — which surfaces the most common values for filtering — this is the documented, bounded trade-off; the read takes top-50, well inside the per-day cap.