In Telegram streaming, the typing indicator persisted through the slow
final rich-text/MarkdownV2 finalize edit, so the '...typing' bubble
lingered for seconds after the last streamed token. Add a one-shot
on_before_finalize hook to GatewayStreamConsumer, fired once when the
stream transitions into its finalization path, and wire it on both
Telegram streaming call sites to call pause_typing_for_chat() before
the final edit. Cover hook ordering and once-only behavior in tests.
Fixes#49712
LeonSGP43
09a96ba0f6