Match shell squircle outlines with compositor masks

Use shared corner geometry for shell controls, window clipping, materials and blur masks. Preserve circular pills and controls where appropriate, track contour changes in damage, and use tagged ferese-shape and libcosmic dependencies.

shell/ferese-shell/src/status_ui/controls.rs

@@ -1,3 +1,4 @@
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::iced::{Alignment, Background, Border, Color, Length};
 use cosmic::widget::{button, column, container, row, slider};
 use cosmic::{Element, theme};
@@ -32,6 +33,7 @@ pub(super) fn status_summary<'a>(
                 ..badge_color
             })),
             border: Border {
+                shape: BorderShape::Continuous,
                 radius: motion::radius(16.0).into(),
                 ..Default::default()
             },
@@ -79,6 +81,7 @@ pub(super) fn level_meter(value: u8, foreground: Color, opacity: f32) -> Element
                     }
                 })),
                 border: Border {
+                    shape: BorderShape::Continuous,
                     radius: motion::radius(2.5).into(),
                     ..Default::default()
                 },