pub fn clear_app_theme()Expand description
Clear a previously-set override, returning to the platform’s own
light/dark-derived default theme on the next poll (see set_app_theme).
A no-op call (no override was ever set) still bumps the generation, so a
watcher that polled before any set_app_theme/clear_app_theme call
and one that polls after a redundant clear_app_theme both observe the
same “no override” state deterministically rather than depending on
whether the slot happened to already be None.