feat(ui): add configurable Iced themes

src/ui/popup/scale_popup.rs

@@ -1,7 +1,7 @@
 //! Annotation / viewport scale status menu.
 
 use iced::widget::{button, row, text};
-use iced::{Background, Color, Element, Fill, Theme};
+use iced::{Element, Fill};
 
 use crate::app::Message;
 use crate::ui::statusbar::status_menu::Entry;
@@ -44,66 +44,25 @@ pub fn menu_entries(
 }
 
 fn scale_row(label: String, active: bool, msg: Message) -> Element<'static, Message> {
-    let check = crate::ui::icons::check_cell(active, CHECK_COLOR);
+    let check = crate::ui::icons::themed_check_cell(active);
 
-    let lbl = text(label)
-        .size(11)
-        .color(if active { LABEL_ON } else { LABEL_OFF });
+    let lbl = text(label).size(11);
 
     let content = row![check, lbl].spacing(6).align_y(iced::Center);
 
     button(content)
         .on_press(msg)
-        .style(|_: &Theme, status| button::Style {
-            background: Some(Background::Color(match status {
-                button::Status::Hovered => ROW_HOVER,
-                _ => Color::TRANSPARENT,
-            })),
-            ..Default::default()
-        })
+        .style(button::subtle)
         .width(Fill)
         .padding([4, 10])
         .into()
 }
 
 fn manage_row() -> Element<'static, Message> {
-    button(text("Manage...").size(11).color(CHECK_COLOR))
+    button(text("Manage...").size(11))
         .on_press(Message::ScaleManagerOpen)
-        .style(|_: &Theme, status| button::Style {
-            background: Some(Background::Color(match status {
-                button::Status::Hovered => ROW_HOVER,
-                _ => Color::TRANSPARENT,
-            })),
-            ..Default::default()
-        })
+        .style(button::primary)
         .width(Fill)
         .padding([5, 10])
         .into()
 }
-
-// ── Colours ───────────────────────────────────────────────────────────────
-
-const ROW_HOVER: Color = Color {
-    r: 0.22,
-    g: 0.22,
-    b: 0.22,
-    a: 1.0,
-};
-const CHECK_COLOR: Color = Color {
-    r: 0.35,
-    g: 0.75,
-    b: 1.00,
-    a: 1.0,
-};
-const LABEL_ON: Color = Color {
-    r: 0.92,
-    g: 0.92,
-    b: 0.92,
-    a: 1.0,
-};
-const LABEL_OFF: Color = Color {
-    r: 0.65,
-    g: 0.65,
-    b: 0.65,
-    a: 1.0,
-};