Root plate: the toolkit's standard spec, not a hand-rolled fill

The window base was a full-window rounded_rect at the silhouette radius
(with a quad fallback) in a hand-picked colour. It is now
PaintCtx::root_plate(w, h) — cce-ui's PlateSpec::window: the DE root
material at its configured opacity, four window corners, the standard
rolled rim. The menubar and statusbar bands are untouched in this pass.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

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

diff --git a/src/main.rs b/src/main.rs
index d53d37d..a9b1904 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -429,14 +429,14 @@ impl Application for TextEditorApp {
         let w = self.width as f32;
         let h = self.height as f32;
         let status_y = h - 30.0;
+        // The standard root plate (cce-ui PlateSpec::window).
+        pc.root_plate(w, h);
         // Silhouette radius (cce-ui RFC 7b): matches the compositor clip.
         let radius = cce_ui::layout::window_silhouette_radius();
         if radius > 0.1 {
-            pc.rounded_rect(Rect { x: 0.0, y: 0.0, width: w, height: h }, radius, (true, true, true, true), [0.05, 0.05, 0.07, 1.0]);
             pc.rounded_rect(Rect { x: 0.0, y: 0.0, width: w, height: 42.0 }, radius, (true, true, false, false), [0.08, 0.08, 0.12, 1.0]);
             pc.rounded_rect(Rect { x: 0.0, y: status_y, width: w, height: 30.0 }, radius, (false, false, true, true), [0.08, 0.08, 0.10, 1.0]);
         } else {
-            pc.quad(Rect { x: 0.0, y: 0.0, width: w, height: h }, [0.05, 0.05, 0.07, 1.0]);
             pc.quad(Rect { x: 0.0, y: 0.0, width: w, height: 42.0 }, [0.08, 0.08, 0.12, 1.0]);
             pc.quad(Rect { x: 0.0, y: status_y, width: w, height: 30.0 }, [0.08, 0.08, 0.10, 1.0]);
         }