Archive, Leave, Unarchive and Delete in channel settings waited for the
relay and then popped whatever route was on top of the root navigator.
If the user closed the settings sheet during that wait, the pop removed
Home, leaving an empty navigator: a blank screen with no way back.
Close only the sheet or page that offered the action, and only while it
is still open. Make Home's route refuse pops, reporting them as errors,
so no stray pop can empty the navigator again.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tom Brow <tomb@squareup.com>