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/ToolsGrid.tsx

@@ -68,6 +68,18 @@ const tools = [
       </svg>
     ),
   },
+  {
+    title: 'Draw',
+    description: 'Virtual whiteboard for sketching hand-drawn style diagrams. Create flowcharts, wireframes, and visual brainstorming with collaborative editing.',
+    url: 'https://draw.kit.pivoine.art',
+    gradient: 'gradient-orange-pink',
+    badges: ['Collaborative', 'Open Source', '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="M15.232 5.232l3.536 3.536m-2.036-5.036a2.5 2.5 0 113.536 3.536L6.5 21.036H3v-3.572L16.732 3.732z" />
+      </svg>
+    ),
+  },
 ];
 
 export default function ToolsGrid() {