feat: add class registration pages for enrollment and class requests.

Wire class cards to payment flows with plan terms, user provisioning, and a disabled pay button until the gateway is ready.

src/api/classesApi.js

@@ -2,5 +2,6 @@ import axiosInstance from './axiosInstance'
 
 export const classesApi = {
   getAll: (params = {}) => axiosInstance.get('/classes/user/get-all', { params }),
+  getOne: (id) => axiosInstance.get(`/classes/user/get-one/${id}`),
   getMyClasses: (params = {}) => axiosInstance.get('/classes/user/my-classes', { params })
 }