auto-claude: subtask-1-3 - Display reading time on blog post detail page

- Import Clock icon from lucide-react
- Export calculateReadingTime function from blog.ts
- Calculate reading time for post content
- Display reading time in post header with Clock icon
- Format matches listing page: "X min read"

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/lib/blog.ts

@@ -71,7 +71,7 @@ function detectCategory(filename: string, content: string): string {
   return 'Technologie';
 }
 
-function calculateReadingTime(content: string): number {
+export function calculateReadingTime(content: string): number {
   // Remove markdown syntax for more accurate word count
   const text = content
     .replace(/```[\s\S]*?```/g, '') // Remove code blocks