feat: implement customer registration flow and business hours system

Major changes:
- Add customer registration with email/phone lookup (app/booking/registro)
- Add customers API endpoint (app/api/customers/route)
- Implement business hours for locations (mon-fri 10-7, sat 10-6, sun closed)
- Fix availability function type casting issues
- Add business hours utilities (lib/utils/business-hours.ts)
- Update Location type to include business_hours JSONB
- Add mock payment component for testing
- Remove Supabase auth from booking flow
- Fix /cita redirect path in booking flow

Database migrations:
- Add category column to services table
- Add business_hours JSONB column to locations table
- Fix availability functions with proper type casting
- Update get_detailed_availability to use business_hours

Features:
- Customer lookup by email or phone
- Auto-redirect to registration if customer not found
- Pre-fill customer data if exists
- Business hours per day of week
- Location-specific opening/closing times

app/booking/layout.tsx

@@ -8,7 +8,12 @@ import { useAuth } from '@/lib/auth/context'
 import { loadStripe } from '@stripe/stripe-js'
 import { Elements } from '@stripe/react-stripe-js'
 
-const stripePromise = loadStripe(process.env.NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY!)
+const STRIPE_ENABLED = process.env.NEXT_PUBLIC_STRIPE_ENABLED === 'true'
+const STRIPE_KEY = process.env.NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY
+
+const stripePromise = STRIPE_ENABLED && STRIPE_KEY && !STRIPE_KEY.includes('your_stripe_')
+  ? loadStripe(STRIPE_KEY)
+  : null
 
 export default function BookingLayout({
   children,
@@ -16,8 +21,9 @@ export default function BookingLayout({
   children: ReactNode
 }) {
   const { user, signOut, loading } = useAuth()
-  return (
-    <Elements stripe={stripePromise}>
+
+  const content = (
+    <>
       <header className="site-header booking-header">
         <nav className="nav-primary">
           <div className="logo">
@@ -72,6 +78,8 @@ export default function BookingLayout({
       <main className="pt-24">
         {children}
       </main>
-    </Elements>
+    </>
   )
+
+  return stripePromise ? <Elements stripe={stripePromise}>{content}</Elements> : content
 }