fix: block viewer copy install command

[zjom]

When copying the install command from the blocks page, it only copies npx shadcn@latest add , foregoing the actual block name.

The issue is in the copyToClipboard function call in block-viewer.tsx where it doesn't reference item.name, only name.

[vercel]

@zjom is attempting to deploy a commit to the shadcn-pro Team on Vercel.

A member of the Team first needs to authorize it.

[shadcn]

Fixed in #5790