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/Stats.tsx

@@ -4,7 +4,7 @@ import { motion } from 'framer-motion';
 
 const stats = [
   {
-    number: '7',
+    number: '6',
     label: 'Tools',
     icon: (
       <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">