Apply dark theme to all UI pages

- Convert registry list, docker detail, package detail, maven detail pages to dark theme
- Use layout_dark instead of layout for all pages
- Update colors: bg-[#1e293b] cards, slate-700 borders, slate-200/400 text
- Mark unused light theme functions with #[allow(dead_code)]

deploy/nora-demo-traffic.service

@@ -0,0 +1,15 @@
+[Unit]
+Description=NORA Demo Traffic Simulator
+After=docker.service
+Requires=docker.service
+
+[Service]
+Type=simple
+ExecStart=/opt/nora/demo-traffic.sh
+Restart=always
+RestartSec=10
+StandardOutput=journal
+StandardError=journal
+
+[Install]
+WantedBy=multi-user.target