SDK 0.16.1

A regeneration that changes no type, field, method or status code. The API's
change feeds behave differently, and the doc comments in all four languages now
say how.

Documented

• Every change feed reads two minutes behind the server clock. A page only
  contains rows whose updatedAtUtc is at least two minutes old, and
  serverTimeUtc is the server clock minus that delay, never older than a row
  on the page. The server stamps a row before it commits it, so a feed reading
  up to the present could hand out a cursor beyond a row that was not visible
  yet, and that row was never returned. Changes now reach a consumer up to two
  minutes later; persisting serverTimeUtc as the next since after an empty
  page stays correct. A stored cursor newer than the bound gets empty pages
  until the bound passes it. This applies to all ten /…/changes feeds; see
  Catalogue synchronization.

• GET /video-user-images/changes no longer exposes hidden images. An image
  that is deleted, or hidden, denied or removed in moderation, is reported with
  eventType: "deleted", an empty url and a null vttUrl; a restored image
  reappears as updated with its URLs. url remains a non-nullable string, so
  the generated types are unchanged; treat "" as "no image".

Closes #47. Issue #35 remains open pending an upstream API extension.

Validation: CI passed for Python, TypeScript (Node 22 and 24), Go, C# (.NET 8 and 10), and generated-code consistency.