add settings dialog

crates/signed_app/src/app/helpers.rs

@@ -4,7 +4,12 @@ use settings::{AppearanceMode, Settings};
 
 /// Applies the persisted light/dark/system preference to the kit theme.
 pub fn apply_appearance(settings: &Settings, cx: &mut App) {
-    match settings.appearance {
+    apply_appearance_mode(settings.appearance, cx);
+}
+
+/// Applies one appearance mode to the kit theme.
+pub fn apply_appearance_mode(mode: AppearanceMode, cx: &mut App) {
+    match mode {
         AppearanceMode::System => follow_system(cx),
         AppearanceMode::Light => set_mode_override(Some(ThemeVariant::Light), cx),
         AppearanceMode::Dark => set_mode_override(Some(ThemeVariant::Dark), cx),