Persisted posting price annotation (embedded schema).
Storage-layer counterpart of a Beancount.Directives.Posting :price map
(@/@@). Embedded inside Beancount.Schemas.Posting via embeds_one/3;
it has no table of its own.
Storing the price as a typed embedded schema (rather than a bare map) keeps
amount a Decimal.t() across a database round-trip, so rendering the loaded
directive produces byte-identical Beancount text.
Fields
amount- price quantity asDecimal.t().currency- commodity ofamount.type-"unit"for@(per-unit) or"total"for@@(total) price.
Example
%Beancount.Schemas.PriceAnnotation{
amount: Decimal.new("197.90"),
currency: "USD",
type: "unit"
}