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/api/availability/staff-unavailable/route.ts

@@ -1,5 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server'
-import { supabaseAdmin } from '@/lib/supabase/client'
+import { supabaseAdmin } from '@/lib/supabase/admin'
 
 async function validateAdminOrStaff(request: NextRequest) {
   const authHeader = request.headers.get('authorization')