Add Proyecciones page with yearly financial projections view

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

frontend/src/components/Layout.tsx

@@ -7,6 +7,7 @@ import {
   PiggyBank,
   Droplets,
   LogOut,
+  TrendingUp,
   Wallet,
   Menu,
   Sun,
@@ -51,6 +52,7 @@ const navSections: NavSection[] = [
       { to: '/budget', icon: Calculator, label: 'Presupuesto' },
       { to: '/salarios', icon: Landmark, label: 'Salarios' },
       { to: '/pensions', icon: PiggyBank, label: 'Pensiones' },
+      { to: '/proyecciones', icon: TrendingUp, label: 'Proyecciones' },
       { to: '/analytics', icon: BarChart3, label: 'Analytics' },
     ],
   },