shelf_rise and shelf_fall are changes to the regular price;
promotion_started and promotion_ended are changes in what was paid while
the regular price stayed the same (a product at 18 euro on promotion and 23
euro after is a promotion ending, not a 27.8% price rise); loyalty_change
is a Clubcard price moving; pack_change is the same product in a different
pack size, confirmed over three days of records (a smaller pack at the same
price is a hidden rise). on_promotion_both_dates marks a shelf change in
the label's "was" price while the offer price paid did not move.

Each mover returned costs one credit; the summaries are free.

Args:
    from_date: the earlier date, YYYY-MM-DD (prices recorded since May 2026).
    to_date: the later date, YYYY-MM-DD; defaults to today.
    group: a kind of product: beer, cider, wine, spirits, alcohol, or any
        product type such as breakfast cereal, butter, coffee, crisps,
        nappies. Narrower words work too ("vodka", "red wine").
    query: product or brand words, with or without group
        (e.g. "guinness").
    category: an aisle name to narrow by.
    store: aldi, tesco, supervalu or dunnes; leave out for all four.
    kinds: which lists to return (default all six).
    rank_by: "pct" (default) or "eur".
    limit: most products per list (default 10, max 50).