Feed of service change events

Returns change events detected on the live x402 wire: a payTo (settlement address) rotation, a price move, or a schema change (endpoints, networks, assets, or protocol version added or removed). Each event is diffed from the ENTIRE accepts[] a service returns on every probe, so a payTo rotation at an unchanged price - invisible to price-only tracking - shows up here. Newest first, over a rolling window (days). Events are retained perpetually; the window only bounds the feed. meta.type_counts breaks the window down by event type and meta.window_total gives the events in it, so ONE call returns all four figures (before, the breakdown took a filtered call per type plus one more for the total). Both cover the whole window: they are scoped by days and by the service filter, but NOT by the type filter. So with ?type=price_changed, meta.total counts the filtered feed you are paging while meta.type_counts still reports every type; the two are meant to differ. Each type in the enum is always present, 0 included, and type_counts sums to meta.window_total while every event carries one of the enum types; a type not yet in the enum still counts toward window_total but into no bucket.