feat: add services module with AI predictions

Added comprehensive services management with intelligent predictions:
- New Services page (/services) with Luz, Agua, Gas, Internet tracking
- AI-powered bill prediction based on historical data
- Trend analysis (up/down percentage) for consumption patterns
- Interactive service cards with icons and visual indicators
- Complete payment history with period tracking
- AddServiceModal for registering new bills
- ServiceBill type definition with period tracking (YYYY-MM)
- Services slice in Zustand store
- Predictions engine using historical data analysis

🤖 Generated with [Claude Code](https://claude.com/claude-code)

components/layout/Sidebar.tsx

@@ -6,6 +6,7 @@ import {
   CreditCard,
   PiggyBank,
   Bell,
+  Lightbulb,
   X,
 } from 'lucide-react';
 import Link from 'next/link';
@@ -23,6 +24,7 @@ const navigationItems = [
   { name: 'Deudas', href: '/debts', icon: Wallet },
   { name: 'Tarjetas', href: '/cards', icon: CreditCard },
   { name: 'Presupuesto', href: '/budget', icon: PiggyBank },
+  { name: 'Servicios', href: '/services', icon: Lightbulb },
   { name: 'Alertas', href: '/alerts', icon: Bell, hasBadge: true },
 ];
 
@@ -88,10 +90,9 @@ export function Sidebar({
                       className={`
                         flex items-center gap-3 px-3 py-2.5 rounded-lg text-sm font-medium
                         transition-colors relative
-                        ${
-                          active
-                            ? 'bg-slate-800 text-emerald-400 border-l-2 border-emerald-500'
-                            : 'text-slate-300 hover:bg-slate-800 hover:text-slate-100'
+                        ${active
+                          ? 'bg-slate-800 text-emerald-400 border-l-2 border-emerald-500'
+                          : 'text-slate-300 hover:bg-slate-800 hover:text-slate-100'
                         }
                       `}
                     >