refactor: add primitives, plan mode display, and new session model selector

src/shared/view/ui/Shimmer.tsx

@@ -0,0 +1,26 @@
+import * as React from 'react';
+
+import { cn } from '../../../lib/utils';
+
+interface ShimmerProps {
+  children: string;
+  className?: string;
+  as?: React.ElementType;
+}
+
+const Shimmer = React.memo<ShimmerProps>(({ children, className, as: Component = 'span' }) => {
+  return (
+    <Component
+      className={cn(
+        'animate-shimmer inline-block bg-[length:250%_100%] bg-clip-text text-transparent',
+        'bg-[linear-gradient(90deg,transparent_33%,hsl(var(--foreground))_50%,transparent_67%),linear-gradient(hsl(var(--muted-foreground)),hsl(var(--muted-foreground)))]',
+        className
+      )}
+    >
+      {children}
+    </Component>
+  );
+});
+Shimmer.displayName = 'Shimmer';
+
+export { Shimmer };