Get Organization Global Control Stats

Aggregate cohort counts for one org.

enabled_at echoes the org's write-once enable timestamp; pct echoes the current dice-roll percentage. The four counts answer:

• treated_count — every contact with is_global_control = false across the org's lifetime (includes pre-enable grandfather-treated).
• control_count — every contact with is_global_control = true. By construction this equals control_since_enable_count because the dice roll only fires when enabled_at is set; the field is included for symmetry with the totals row.
• treated_since_enable_count — treated contacts created at-or-after enabled_at. Pair with control_since_enable_count to compute the realized percentage (denominator for the "does this match my configured pct" sanity check). Zero when enabled_at IS NULL.
• control_since_enable_count — see treated_since_enable_count.