fix: correct Audio gradient class name

- Change gradient-orange-red to gradient-orange-pink
- Use correct gradient class that exists in globals.css
- Fixes missing colors on Audio tool card

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

components/ToolsGrid.tsx

@@ -38,7 +38,7 @@ const tools = [
     title: 'Audio',
     description: 'Professional browser-based audio editor with multi-track editing, advanced effects, and real-time analysis. Record, edit, and export to WAV, MP3, OGG, or FLAC entirely in your browser.',
     url: 'https://audio.kit.pivoine.art',
-    gradient: 'gradient-orange-red',
+    gradient: 'gradient-orange-pink',
     accentColor: '#f97316',
     badges: ['Open Source', 'Audio Editor', 'Free'],
     icon: (