feat: add ExamStageActions component for exam fee handling

- Implemented ExamStageActions component to manage actions related to exam booking and payment based on application status.
- Added mock-base-query for development, providing a partial mock backend for various API endpoints.
- Introduced mock-data for simulating responses in the mock-base-query, covering profiles, vessels, applications, licenses, exams, and notifications.

apps/backoffice/src/app/layouts/BackofficeLayout.tsx

@@ -35,7 +35,16 @@ export function BackofficeLayout() {
   const [collapsed, setCollapsed] = useState(false);
   const user = useAppSelector((state) => state.auth.user);
   const layoutMode = useAppSelector((state) => state.preferences.layoutMode);
-  const { can } = usePermissions();
+  const { permissions: granted, known } = usePermissions();
+
+  // TEMPORARY diagnostic — remove once the sidebar is confirmed working.
+  // eslint-disable-next-line no-console
+  console.log(
+    '[NAV] known=', known,
+    'granted=', granted.length,
+    '| cookies:', document.cookie.split('; ').map((c) => c.split('=')[0]).filter((n) => n.includes('token')),
+    '| token tail:', (document.cookie.match(/ema-backoffice-auth-token=([^;]+)/)?.[1] ?? 'NONE').slice(-12),
+  );
 
   // Badges reflect real pending work. One grouped request on a timer, shared
   // by the sidebar and the top bar via the RTK cache.
@@ -53,17 +62,10 @@ export function BackofficeLayout() {
           : item,
       ),
     }));
-    return filterByPermissions(
-      withBadges,
-      // `can` already fails open when the token carries no permission claim,
-      // so this only ever removes items we are sure the user cannot use.
-      withBadges
-        .flatMap((section) => section.items)
-        .flatMap((item) => [item, ...(item.children ?? [])])
-        .flatMap((item) => item.permissions ?? [])
-        .filter((permission) => can([permission])),
-    );
-  }, [counts?.unassigned, can]);
+    // Unfiltered until the grant list has loaded, matching PortalLayout and
+    // RequirePermission: a moment of extra nav beats a flash of empty nav.
+    return known ? filterByPermissions(withBadges, granted) : withBadges;
+  }, [counts?.unassigned, granted, known]);
 
   /** Flat list used for breadcrumbs and active-route lookup. */
   const navItems = useMemo<NavItem[]>(