Opening someone's link prepares a chat and shows the profile picker above the
compose box. It listed existing profiles and Incognito, so connecting as
someone new meant leaving the invitation, creating a profile in settings, and
coming back to the link.
Adds "Add profile" to that picker, reusing the existing users_add string. The
profile is created without becoming active, so the profile that owns the
prepared chat stays active for the reassignment, which then switches once -
rather than switching away and back.
The row is emitted last, so with the reversed layout it renders at the top of
the expanded list with the current selection nearest the compose box.
After switching, the chat is reopened explicitly: keepingChatId only preserves
its place in the reloaded list, so without that the switch lands on the chat
list of the new profile rather than the invitation it was chosen for. This
applies to picking an existing profile too.
The form is only dismissed once creation succeeds, so a rejected duplicate name
does not discard what was typed. A dismissal guard keeps a back-tap during
creation from switching the profile anyway, and the created profile is put into
the picker list immediately so it stays visible if the reassignment fails.
If the core activated the profile despite keepActiveUser - an older remote host
ignoring the field - the reassignment would fail, so that case resyncs to what
the host actually did instead.
Updates the onboarding flow doc, which names the arguments of the command that
gains the field.
Narasimha-sc