chore: import upstream snapshot with attribution

apps/docs/components/ui/code-block.tsx

@@ -0,0 +1,44 @@
+'use client'
+
+import { useState } from 'react'
+import { CodeBlock as FumadocsCodeBlock } from 'fumadocs-ui/components/codeblock'
+import { Check, Copy } from 'lucide-react'
+import { cn } from '@/lib/utils'
+
+export function CodeBlock(props: React.ComponentProps<typeof FumadocsCodeBlock>) {
+  const [copied, setCopied] = useState(false)
+
+  const handleCopy = async (text: string) => {
+    await navigator.clipboard.writeText(text)
+    setCopied(true)
+    setTimeout(() => setCopied(false), 2000)
+  }
+
+  return (
+    <FumadocsCodeBlock
+      {...props}
+      className={cn('!border !border-[var(--border)] !shadow-none', props.className)}
+      Actions={({ className }) => (
+        <div className={cn('empty:hidden', className)}>
+          <button
+            type='button'
+            aria-label={copied ? 'Copied Text' : 'Copy Text'}
+            onClick={(e) => {
+              const pre = (e.currentTarget as HTMLElement).closest('figure')?.querySelector('pre')
+              if (pre) handleCopy(pre.textContent || '')
+            }}
+            className='cursor-pointer rounded-md p-2 text-[var(--text-muted)] transition-colors hover:text-[var(--text-icon)]'
+          >
+            <span className='flex items-center justify-center'>
+              {copied ? (
+                <Check size={16} className='text-[var(--brand-accent)]' />
+              ) : (
+                <Copy size={16} className='text-[var(--text-muted)]' />
+              )}
+            </span>
+          </button>
+        </div>
+      )}
+    />
+  )
+}