A payload comparison whose field and literal are both coerced before the
compare, so "2026-09-21T18:04:12Z" orders as an instant and "12.50" as a
number. The coercion is part of the expression and its digest.
How the record payload is decoded before payload predicates run. Chosen
explicitly by the filter: a content-type header never overrides it. A
record whose agdx.ct header names another codec is never decoded, it
follows the filter’s foreign_policy instead.