fix(FN-2444): polish node dashboard UX and discovery core handling

- Update node management UI components to use shared form/button classes, semantic color tokens, and accessible interactions
- Refine mesh topology rendering and related dashboard tests for improved readability and behavior coverage
- Adjust discovery routes to reuse injected centralCore instances without unnecessary init/close cycles
- Add/extend tests for shared CentralCore discovery flows and model settings scope save behavior

packages/dashboard/app/hooks/useNodeSettingsSync.ts

@@ -87,9 +87,9 @@ export function getSyncStateColor(state: SyncState): string {
     case "synced":
       return "var(--color-success)";
     case "pending":
-      return "var(--warning)";
+      return "var(--color-warning)";
     case "diff":
-      return "var(--warning)";
+      return "var(--color-warning)";
     case "error":
       return "var(--color-error)";
     case "never-synced":