Registry of per-bank date-field validators iterated by validateDateConfig.
Legacy order preserved (daysBack → startDate). Mutual-exclusion check
(both set) is performed by validateDateConfig BEFORE the loop, so any
combination that reaches the loop has at most one applicable validator.
Registry of per-bank date-field validators iterated by validateDateConfig.
Legacy order preserved (daysBack → startDate). Mutual-exclusion check (both set) is performed by validateDateConfig BEFORE the loop, so any combination that reaches the loop has at most one applicable validator.