The filtered branch of `getByEndlessListId` applied `LIMIT` without an
`ORDER BY`, so Postgres was free to hand back any matching rows. With a
search over 64 cards the first page returned the oldest ones and a full
cursor walk reached 60 of them across 149 rows — cards both skipped and
repeated. The query now orders the way the cursor reads it.
The cursor itself is validated as ISO 8601, which admits forms Postgres
rejects as a timestamp (`2026`, `2026-W35-3`, a comma as the decimal
separator), each of them a 500 from the adapter. It is normalized before
the query, and stays a string because the equality half of the cursor
reads a `Date` as an empty constraint.
Daniel Hiller