docs(dashboard): add Connecting to the Hub reference page

Covers local setup, remote (COULOMBCORE) one-liner registration,
ops-bridge tunnel config, bridge states, MCP transport modes, and
adding new remote hosts. Registered in Reference nav + reference.md index.

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

dashboard/observablehq.config.js

@@ -43,6 +43,7 @@ export default {
       collapsible: true,
       open: false,
       pages: [
+        { name: "Connecting to the Hub",    path: "/docs/connecting" },
         { name: "Contributions",            path: "/docs/contributions" },
         { name: "Decision Health",          path: "/docs/decisions-kpi" },
         { name: "Decisions",               path: "/docs/decisions" },