fix: restore translucent dashboard styling (#6664)

* fix: restore translucent dashboard styling

* fix: restore dashboard widget transparency

* fix: address dashboard review feedback

* fix: apply board opacity to containers

* fix: flatten demo board container

* fix: default board roundness to sm

* fix: restore assistant widget transparency

* Revert "fix: default board roundness to sm"

This reverts commit c235cbdf2b.

* fix: address remaining dashboard review comments

* test: align grid geometry expectations

packages/widgets/src/audio-stats/component.module.css

@@ -40,7 +40,7 @@
   gap: clamp(2px, 1.5cqi, 4px);
   padding: clamp(4px, 2cqi, 8px);
   border-radius: var(--mantine-radius-md);
-  background-color: light-dark(var(--mantine-color-gray-0), var(--mantine-color-dark-6));
+  background-color: transparent;
   overflow: hidden;
 }