dashboard: add Reference nav section with Live Data and Decision Health docs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

dashboard/observablehq.config.js

@@ -6,6 +6,13 @@ export default {
     { name: "Workstreams", path: "/workstreams" },
     { name: "Decisions", path: "/decisions" },
     { name: "Progress", path: "/progress" },
+    {
+      name: "Reference",
+      pages: [
+        { name: "Live Data", path: "/docs/live-data" },
+        { name: "Decision Health", path: "/docs/decisions-kpi" },
+      ],
+    },
   ],
   theme: ["air", "near-midnight"],
   head: `<link rel="icon" href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>🗄️</text></svg>">`,