Lists the loan files on your processing company's account, as short
summary rows rather than the full detail of each one.

Archived files are left out by default. Two parameters change that and
they are not the same: include_archived=true adds archived files to
the active ones, while archive_state selects — archived for
archived only, active for active only, all for both. Sending both is
allowed and archive_state wins; include_archived is then ignored
rather than rejected. archive_state takes only those three words, and
any other value is a 422 — a silently dropped archived would return
the active list with a 200.

You can also narrow the list by broker, borrower, or loan officer, and
walk through it with page and per_page.

Rows are ordered by loan-file id, highest first, and that order is
stable across pages — page 2 continues below page 1 with no overlap.
The most recently created file is therefore the first row of page 1,
so finding it takes one request rather than a walk of every page.
There is no sort parameter; this is the only ordering available.

createdAt is not the sort key and can disagree with it: a file whose
createdAt holds an earlier date than the row beneath it still sorts
by its id. To order by date, read createdAt from the rows.