refactor(src/shared/styles): replace var(--radius-*) with apply(radius-*) throughout shared styles

Use apply() to align with the updated CSS variable system and ensure consistent radius theming

src/shared/styles/dock.css

@@ -3,8 +3,8 @@
     padding: 4px 4px;
     margin: 4px 4px;
     border: none;
-    border-radius: var(--radius-lg);
-    transition: all var(--transition-fast) cubic-bezier(0.165, 0.84, 0.44, 1);
+    border-radius: apply(radius-lg);
+    transition: all apply(transition-fast) cubic-bezier(0.165, 0.84, 0.44, 1);
 }
 
 #dock.shown {
@@ -54,13 +54,13 @@
 #dock_item_icon {
     border-radius: 13px;
     opacity: 0.7;
-    transition: all var(--transition-fast) cubic-bezier(0.25, 0.1, 0.25, 1);
+    transition: all apply(transition-fast) cubic-bezier(0.25, 0.1, 0.25, 1);
 }
 
 /* #dock_item_indicator { */
 /*   transition: all 0.15s ease-out; */
 /*   min-height: 4px; */
-/*   border-radius: var(--radius-xs); */
+/*   border-radius: apply(radius-xs); */
 /* } */
 
 #dock_item {