Implement activation requirement for protected routes

- Added a new `useRequireActivated` hook to enforce user activation before accessing certain routes, redirecting unauthenticated users to the login page and inactive users to the dashboard.
- Updated the `InstructionsPage` and `NewsPage` components to utilize the new activation check, enhancing user flow and security.
- Conditional rendering of navigation links in the `RootLayout` based on user activation status, improving user experience by hiding inaccessible features.

frontend/src/features/auth/guards.ts

@@ -37,3 +37,17 @@ export function useRequireAdmin() {
 
   return { user, isReady: !isBootstrapping && !!user && user.role === 'admin' }
 }
+
+/** Как useRequireAuth, но дополнительно требует активацию — иначе редирект на дашборд (там форма запроса активации). */
+export function useRequireActivated() {
+  const { user, isBootstrapping } = useAuthStore()
+  const navigate = useNavigate()
+
+  useEffect(() => {
+    if (isBootstrapping) return
+    if (!user) void navigate({ to: '/login' })
+    else if (!user.isActivated) void navigate({ to: '/dashboard' })
+  }, [isBootstrapping, user, navigate])
+
+  return { user, isReady: !isBootstrapping && !!user && user.isActivated }
+}