add muted_hover token and rework tab strip visuals

crates/core/src/button.rs

@@ -41,6 +41,7 @@ pub struct Button {
     size: Size,
     disabled: bool,
     tab_stop: bool,
+    debug_selector: Option<Rc<dyn Fn() -> String>>,
     a11y_label: Option<SharedString>,
     tooltip: Option<TooltipBuilder>,
     on_click: Option<ClickHandler>,
@@ -60,6 +61,7 @@ impl Button {
             size: Size::default(),
             disabled: false,
             tab_stop: true,
+            debug_selector: None,
             a11y_label: None,
             tooltip: None,
             on_click: None,
@@ -102,6 +104,15 @@ impl Button {
         self
     }
 
+    /// Sets the debug-bounds selector, for headless tests.
+    pub fn debug_selector<F>(mut self, selector: F) -> Self
+    where
+        F: Fn() -> String + 'static,
+    {
+        self.debug_selector = Some(Rc::new(selector));
+        self
+    }
+
     /// Renders the button inert, unfocusable, and dimmed.
     pub fn disabled(mut self, disabled: bool) -> Self {
         self.disabled = disabled;
@@ -160,7 +171,7 @@ impl RenderOnce for Button {
             ButtonVariant::Ghost => (
                 None,
                 colors.foreground,
-                colors.muted,
+                colors.muted_hover,
                 ramps.secondary.pressed,
             ),
             ButtonVariant::Destructive => (
@@ -173,6 +184,9 @@ impl RenderOnce for Button {
 
         h_flex()
             .id(self.id)
+            .when_some(self.debug_selector, |button, selector| {
+                button.debug_selector(move || selector())
+            })
             .role(Role::Button)
             .justify_center()
             .when(icon_only, |button| button.size(metrics.control_height))