feat: add Draw (Excalidraw) tool as 6th tool

- Added Draw tool to ToolsGrid with collaborative badges
- Updated Stats component to show 6 tools
- Updated Footer to show 6 tools and include Draw link
- Updated README with Draw tool description
- Draw tool accessible at draw.kit.pivoine.art

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

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

components/Footer.tsx

@@ -24,7 +24,7 @@ export default function Footer() {
               Your Creative Toolkit
             </p>
             <div className="mt-4 inline-flex items-center gap-2 px-3 py-1 rounded-full bg-purple-500/10 border border-purple-500/20">
-              <span className="text-xs font-medium text-purple-400">5 Tools</span>
+              <span className="text-xs font-medium text-purple-400">6 Tools</span>
               <span className="text-gray-600">•</span>
               <span className="text-xs text-gray-500">Open Source</span>
             </div>
@@ -65,6 +65,7 @@ export default function Footer() {
               <a href="https://pastel.kit.pivoine.art" className="text-gray-400 hover:text-purple-400 transition-colors text-sm">Pastel</a>
               <a href="https://stirling.kit.pivoine.art" className="text-gray-400 hover:text-blue-400 transition-colors text-sm">Stirling</a>
               <a href="https://units.kit.pivoine.art" className="text-gray-400 hover:text-cyan-400 transition-colors text-sm">Units</a>
+              <a href="https://draw.kit.pivoine.art" className="text-gray-400 hover:text-pink-400 transition-colors text-sm">Draw</a>
             </div>
           </div>
         </motion.div>