feat(manifest-ui): improve block page meta title and description for SEO

Update meta tags format to better describe shadcn/ui blocks for ChatGPT:
- Title: "$name shadcn/ui block for ChatGPT | Manifest UI"
- Description: "$name ($category): $description"

Author: claude

packages/manifest-ui/app/blocks/[category]/[block]/layout.tsx

@@ -14,10 +14,10 @@ export async function generateMetadata({
 
   const blockName = getBlockName(block)
   const categoryName = getCategoryName(category)
-  const description = getBlockDescription(block, blockName)
+  const blockDescription = getBlockDescription(block, blockName)
 
-  const title = `${blockName} - ${categoryName} Component`
-  const fullTitle = `${title} | Manifest UI`
+  const fullTitle = `${blockName} shadcn/ui block for ChatGPT | Manifest UI`
+  const description = `${blockName} (${categoryName}): ${blockDescription}`
 
   // Preview image URL - generated by the preview generation workflow
   const previewImageUrl = `https://ui.manifest.build/previews/${block}.png`