feat: add validation of free plan

apps/OpenSignServer/cloud/parsefunction/SubscribeFree.js

@@ -0,0 +1,27 @@
+export default async function SubscribeFree(request) {
+  const userId = request.params.userId;
+  const userPtr = { __type: 'Pointer', className: '_User', objectId: userId };
+  try {
+    const extQuery = new Parse.Query('contracts_Users');
+    extQuery.equalTo('UserId', userPtr);
+    const extUser = await extQuery.first({ useMasterKey: true });
+
+    if (extUser) {
+      try {
+        const extUpdate = new Parse.Object('contracts_Users');
+        extUpdate.id = extUser.id;
+        extUpdate.set('Plan', {  plan_code: 'freeplan' });
+        const updatePlan = await extUpdate.save(null, { useMasterKey: true });
+        return { status: 'success', result: 'subscribed!' };
+      } catch (err) {
+        console.log('err ', err);
+        return { status: 'error', result: err.message };
+      }
+    } else {
+      return { status: 'error', result: 'User not found!' };
+    }
+  } catch (err) {
+    console.log('err ', err);
+    return { status: 'error', result: err.message };
+  }
+}