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

lib/supabase/admin.ts

@@ -0,0 +1,16 @@
+import { createClient } from '@supabase/supabase-js'
+
+const supabaseUrl = process.env.NEXT_PUBLIC_SUPABASE_URL!
+const supabaseServiceRoleKey = process.env.SUPABASE_SERVICE_ROLE_KEY!
+
+// Admin Supabase client for server-side operations with service role
+export const supabaseAdmin = createClient(
+  supabaseUrl,
+  supabaseServiceRoleKey,
+  {
+    auth: {
+      autoRefreshToken: false,
+      persistSession: false
+    }
+  }
+)