Add negative label filtering for cards
Two conflicts, both from work that landed while this branch was open.
In the endless list query, master had added an ORDER BY so the cursor and the
limit agree. The exclusion clause belongs in the WHERE part, so it is placed
before it rather than after; the other way round the statement does not parse.
The label item had been restructured here for the tri-state filter and had
gained a tooltip on master. The restructured version is kept and the tooltip
put back on top of it, which also brings back the translation hook this branch
had dropped.
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.