Fix Console Error in Copy-Code Utility

Description

The copy-code utility in src/utils/copy-code.ts logs a console.error when no code content is found to copy. This creates unnecessary console noise and doesn't provide user-friendly feedback when the copy operation fails.

How To Reproduce

1. Go to any page with code blocks (e.g., a blog post with markdown code)
2. Open browser developer tools (F12)
3. Click on a copy button that has no data-code attribute or empty content
4. Check the console tab
5. See error: "No code content found to copy"

Expected behavior

• No console errors should appear during normal usage
• Users should receive visual feedback when copy operation fails
• Error handling should be user-friendly rather than developer-focused

Environment

Desktop

• Operating System: Windows/macOS/Linux (all affected)
• Browser: Chrome, Safari, Firefox (all affected)
• Version: Current main branch

Smartphone

• Device: All devices
• OS: All mobile OS
• Browser: All mobile browsers
• Version: Current main branch

Console Errors

console.error('No code content found to copy');