Setting --error-bg alone had no effect: sonner only honors per-type
surfaces when richColors is enabled, so error toasts kept using
--normal-bg and looked identical to a normal toast. Enable richColors
and pin success/info/warning back to the neutral popover surface so only
errors turn red.
Error toasts previously used the same neutral popover background as
success toasts, so a failure (e.g. a save while the backend is down)
read like a normal 'Canvas saved'. Set sonner's per-type --error-bg/
--error-text/--error-border so errors stand out in red.
Pouzor