feat: add recurring bookings feature with related handlers and services

- Introduced recurring booking groups with the ability to create and cancel them.
- Added database migrations for recurring bookings, including new tables and relationships.
- Implemented handlers for creating and canceling recurring bookings in the admin booking module.
- Enhanced existing booking services to support recurring bookings logic.
- Updated API contract to include new schemas for recurring bookings.
- Refactored existing code for improved readability and maintainability.

apps/backend/prisma/plans.seed-data.ts

@@ -21,6 +21,7 @@ export const planSeeds = [
         publicBookingPage: true,
         advancedReports: false,
         whatsappReminders: false,
+        fixedSlots: false,
       },
       pricing: {
         overrides: {
@@ -51,6 +52,7 @@ export const planSeeds = [
         publicBookingPage: true,
         advancedReports: true,
         whatsappReminders: true,
+        fixedSlots: true,
       },
       pricing: {
         overrides: {
@@ -81,6 +83,7 @@ export const planSeeds = [
         publicBookingPage: true,
         advancedReports: true,
         whatsappReminders: true,
+        fixedSlots: true,
       },
       pricing: {
         overrides: {