feat: add pending student registration flow and pricing APIs.

Support public class lookup, user provisioning, installment pricing, and admin approval before final enrollment.

components/pendingStudents/pendingStudentController.js

@@ -0,0 +1,44 @@
+'use strict';
+
+const catchAsync = require('../../utils/catchAsync');
+const pendingStudentService = require('./pendingStudentService');
+const { successResponse, listResponse } = require('../../utils/apiResponse');
+
+exports.getPricing = catchAsync(async (req, res) => {
+  const preview = await pendingStudentService.getPricingPreview({
+    classId: req.query.classId,
+    type: req.query.type || 'enrollment',
+    paymentPlan: req.query.paymentPlan || 'full'
+  });
+  return successResponse(res, 200, 'Pricing preview retrieved successfully', preview);
+});
+
+exports.ensureUser = catchAsync(async (req, res) => {
+  const result = await pendingStudentService.findOrCreateUser(req.body);
+  return successResponse(res, 200, 'User ensured successfully', result);
+});
+
+exports.completeAfterPayment = catchAsync(async (req, res) => {
+  const pending = await pendingStudentService.createPendingStudentAfterPayment(req.body);
+  return successResponse(res, 201, 'Registration request submitted successfully', pending);
+});
+
+exports.getAll = catchAsync(async (req, res) => {
+  const { data, meta } = await pendingStudentService.getAllPendingStudents(req.query);
+  return listResponse(res, 200, data, meta);
+});
+
+exports.getOne = catchAsync(async (req, res) => {
+  const pending = await pendingStudentService.getPendingStudentById(req.params.id);
+  return successResponse(res, 200, 'Pending student retrieved successfully', pending);
+});
+
+exports.approve = catchAsync(async (req, res) => {
+  const result = await pendingStudentService.approvePendingStudent(req.params.id, req.user._id, req.body);
+  return successResponse(res, 200, 'Pending student approved successfully', result);
+});
+
+exports.reject = catchAsync(async (req, res) => {
+  const result = await pendingStudentService.rejectPendingStudent(req.params.id, req.user._id, req.body);
+  return successResponse(res, 200, 'Pending student rejected successfully', result);
+});