feat: add cameleer3-server-ui container to Docker Compose

The cameleer3-server deploys backend and UI as separate containers.
Add the cameleer3-server-ui image (nginx SPA + API reverse proxy)
to the Compose stack, exposed on port 8082 in dev. Update sidebar
"View Dashboard" link to point to the UI container.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/components/Layout.tsx

@@ -162,7 +162,7 @@ export function Layout() {
         <Sidebar.FooterLink
           icon={<ObsIcon />}
           label="View Dashboard"
-          onClick={() => window.open('http://localhost:8081', '_blank', 'noopener')}
+          onClick={() => window.open('http://localhost:8082', '_blank', 'noopener')}
         />
 
         {/* User info + logout */}