refactor: remove Paint tool from toolkit

- Removed Paint card from ToolsGrid
- Updated Stats from 7 to 6 tools
- Updated Footer badge from 7 to 6 tools
- Removed Paint link from Footer tools column
- Removed Paint from README Available Tools section

Current tools (6):
- Vert (file converter)
- Pastel (color toolkit)
- Stirling (PDF toolkit)
- Units (unit converter)
- Draw (whiteboard)
- Figlet (ASCII art)

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

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

components/ToolsGrid.tsx

@@ -17,19 +17,6 @@ const tools = [
       </svg>
     ),
   },
-  {
-    title: 'Paint',
-    description: 'An advanced image editor running in your browser. Edit photos, create graphics, and more.',
-    url: 'https://paint.kit.pivoine.art',
-    gradient: 'gradient-orange-pink',
-    accentColor: '#f97316',
-    badges: ['Browser-Based', 'Free'],
-    icon: (
-      <svg className="w-12 h-12 text-white" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M7 21a4 4 0 01-4-4V5a2 2 0 012-2h4a2 2 0 012 2v12a4 4 0 01-4 4zm0 0h12a2 2 0 002-2v-4a2 2 0 00-2-2h-2.343M11 7.343l1.657-1.657a2 2 0 012.828 0l2.829 2.829a2 2 0 010 2.828l-8.486 8.485M7 17h.01" />
-      </svg>
-    ),
-  },
   {
     title: 'Pastel',
     description: 'Modern color manipulation toolkit with palette generation, accessibility testing, and format conversion. Supports hex, RGB, HSL, Lab, and more.',