- Edit Bot now shows the current value of every field (Name/About/
Description/Botpic/Commands) like BotFather, with real botpic status
via a new PeerHasAvatar port method.
- After editing a field the dialog lands back on a fresh Edit Bot menu
(working "Back to bot" / "Bots list" buttons) instead of ending, so a
follow-up button press no longer reports the button as expired.
- Service-bot messages now render @username as a tappable mention entity.
