Returns one record per contract, for any Daml template on the participant, with the
contract's create arguments passed through verbatim as payload. Where the typed
endpoints (/token/*, /dtcc/*) normalise a handful of known templates into a fixed
shape, this endpoint exposes every template the caller's party scope can see — a
trading venue's CashDvp, a settlement-app Dvp/SettledDvp, an application's own workflow
contract — without this API needing to know its shape in advance.

This is state, not events. Each record is a contract as it stands: status: open
means the contract is currently active; status: closed (returned only with
includeArchived=true) means it has been archived. The record does not say which
choice archived it — for the sequence of creates and exercises, use /native/updates.
A typical integration polls this endpoint for the templates it cares about and joins
records on an application-level key carried in payload (a trade id, for example).

Always filter. Without templateId or packageName the query spans every
template on the participant, which is dominated by housekeeping records (see the note
on volume under /native/updates). packageName is the cheapest filter;
templateId is the precise one.

payload is the contract's create arguments as the ledger holds them, in Daml-LF
JSON encoding: decimals are strings, timestamps are ISO-8601 strings, parties are full
party identifiers, and optional fields are absent rather than null. Its shape is
defined by the template, not by this API.