chore: root_plate_* — cce-ui 7a-2 caller migration

Mechanical rename onto cce-ui's canonical root-plate getters
(cce-ui@c8e0ab3, RFC Phase 7a); behavior unchanged, same config slots.

 src/main.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index ea4a429..1a6ddcc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1253,7 +1253,7 @@ impl State {
         cce_ui::scale::set_app_id("cce-cloud".to_string());
         let bg_color = cce_ui::color::page_low_color();
         let window_rect = (0.0, 0.0, lw, lh);
-        let window_radius = cce_ui::color::backplate_corner_radius();
+        let window_radius = cce_ui::color::root_plate_corner_radius();
 
         let mut state = Self {
             window: Some(window),
@@ -1483,7 +1483,7 @@ impl State {
         // rim makes the popup read as a raised surface instead of a flat sheet.
         let mut bg_color = self.window_bg;
         if bg_color[3] > 0.001 {
-            bg_color[3] = cce_ui::color::active_backplate_opacity();
+            bg_color[3] = cce_ui::color::root_plate_opacity();
         }
         if bg_color[3] > 0.0 {
             let r = if self.window_radius > 0.1 { self.window_radius } else { 0.0 };