feat: add customer email functionality for booking confirmations

- Implemented email confirmation for admin and public bookings.
- Added customerEmail field to booking schemas and services.
- Created email templates for booking confirmation, cancellation, and no-show notifications.
- Updated booking handlers to send emails upon booking creation and status updates.
- Enhanced frontend forms to capture customer email during booking creation.

apps/backend/prisma/court.prisma

@@ -85,6 +85,7 @@ model CourtBooking {
   endTime       String              @map("end_time") @db.VarChar(5)
   customerName  String              @map("customer_name") @db.VarChar(120)
   customerPhone String              @map("customer_phone") @db.VarChar(30)
+  customerEmail String?             @map("customer_email") @db.VarChar(254)
   status        CourtBookingStatus  @default(CONFIRMED)
   createdAt     DateTime            @default(now()) @map("created_at")
   updatedAt     DateTime            @updatedAt @map("updated_at")
@@ -107,6 +108,7 @@ model CourtBookingLog {
   newStatus      CourtBookingStatus  @map("new_status")
   customerName  String               @map("customer_name") @db.VarChar(120)
   customerPhone String               @map("customer_phone") @db.VarChar(30)
+  customerEmail String?              @map("customer_email") @db.VarChar(254)
   changedAt      DateTime            @default(now()) @map("changed_at")
 
   @@map("court_booking_logs")

apps/backend/prisma/migrations/20260602220943_add_customer_email/migration.sql

@@ -0,0 +1,14 @@
+/*
+  Warnings:
+
+  - You are about to drop the `onboarding_requests` table. If the table is not empty, all the data it contains will be lost.
+
+*/
+-- AlterTable
+ALTER TABLE "court_booking_logs" ADD COLUMN     "customer_email" VARCHAR(254);
+
+-- AlterTable
+ALTER TABLE "court_bookings" ADD COLUMN     "customer_email" VARCHAR(254);
+
+-- DropTable
+DROP TABLE "onboarding_requests";