Group discovered runs by (date, articleType) so callers can decide
whether a collision-suffix is needed when writing articles.
Insertion order is preserved within each bucket — the batch driver
iterates the original runs list in order and looks up its own bucket
by key, so the collision-suffix is appended deterministically.
Group discovered runs by
(date, articleType)so callers can decide whether a collision-suffix is needed when writing articles.Insertion order is preserved within each bucket — the batch driver iterates the original
runslist in order and looks up its own bucket by key, so the collision-suffix is appended deterministically.