Add Pensions page with fund overview, growth chart, and projections

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/Layout.tsx

@@ -4,6 +4,7 @@ import {
   Calculator,
   BarChart3,
   Landmark,
+  PiggyBank,
   LogOut,
   Wallet,
   Menu,
@@ -29,6 +30,7 @@ const navItems = [
   { to: '/', icon: LayoutDashboard, label: 'Dashboard' },
   { to: '/budget', icon: Calculator, label: 'Presupuesto' },
   { to: '/salarios', icon: Landmark, label: 'Salarios' },
+  { to: '/pensions', icon: PiggyBank, label: 'Pensiones' },
   { to: '/analytics', icon: BarChart3, label: 'Analytics' },
 ];