feat(ui): expand reusable component foundation

- add Base UI and shadcn primitives for overlays, forms, navigation, feedback, and data display

- add optimized DOM ripple hooks with ref composition and integrate the behavior into interactive controls

- add AnchoredSurface SVG geometry and arrow-aware popover, dropdown, and tooltip rendering

- extend responsive breakpoint and style utilities, declare component dependencies, and remove the redundant package ESLint config

packages/ui/src/components/skeleton.tsx

@@ -0,0 +1,13 @@
+import { cn } from "@workspace/ui/lib/utils"
+
+function Skeleton({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="skeleton"
+      className={cn("animate-pulse rounded-md bg-muted", className)}
+      {...props}
+    />
+  )
+}
+
+export { Skeleton }