Redirect direct GETs of booking-process to home

Hitting /booking-process via GET (or any POST without sendBooking) fell
through past the form-submit guard and tripped three undefined-variable
warnings on the final sendEmail() call. Bail out to the site root
early, matching the pattern in manage_booking_process.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

application/controllers/Pages.php

@@ -284,6 +284,11 @@ class Pages extends CI_Controller {
 		$data['pageTitle'] = '';
 		$data['subpage'] = '';
 
+		if(!isset($_POST['sendBooking'])){
+			header('Location:'.SITEURL);
+			return;
+		}
+
 		if(isset($_POST['sendBooking'])){
 			//calculate finish time
 			$serviceStartTime = date("H:i:s", strtotime($_POST['booking_start_time']));