Builder retention cohorts

Retention matrix for the builder's users: wallets are cohorted by the calendar month (or ISO week, with granularity=weekly) of their first activity via this builder, and each later period counts how many of that cohort were active again. WHICH PLANE defines 'first' and 'active' is disclosed per response in dataNotes: the attribution rollup's presence rows (at least one attributed fill that period) whenever it can serve the builder, otherwise the orders plane (at least one builder-fee order placed that period — the order need not fill, so those counts can exceed the attributed-fill user counts on the cohorts and overlap endpoints). Oldest cohort first; each cohort's activeWallets series starts at its own period (index 0 == newWallets). revenueWeighted=true adds a parallel activeRevenueUsd fee series, cohorted identically to activeWallets; covers the last 12 months or 16 weeks depending on granularity.