Finish CUST-WP-0011 and implement STATE-WP-0061 suggestion backlog.

Add persisted Suggestion entities with WSJF ranking, relevance bumps,
REST/MCP write surfaces, /suggestions dashboard page, and daily triage
digest integration. Document the cluster operating model, archive the
completed migration workplan, and seed WARDEN-WP-0012 routing scenarios.

dashboard/observablehq.config.js

@@ -81,6 +81,7 @@ export default {
         { name: "Interventions", path: "/interventions" },
         { name: "Tasks",         path: "/tasks" },
         { name: "UI Feedback",   path: "/ui-feedback" },
+        { name: "Suggestions",   path: "/suggestions" },
         { name: "WSJF Triage",   path: "/wsjf-triage" },
       ],
     },
@@ -122,6 +123,7 @@ export default {
         { name: "Workstream Health",        path: "/docs/workstream-health-index" },
         { name: "Workstream Lifecycle",     path: "/docs/workstream-lifecycle" },
         { name: "Workstreams",              path: "/docs/workstreams" },
+        { name: "Suggestions",              path: "/docs/suggestions" },
         { name: "WSJF Triage",              path: "/docs/wsjf-triage" },
       ],
     },