fix: add null guards to prevent unhandled exceptions

- Add fallback for job.data.data in webhooks worker to prevent TypeError
- Reset outlookSubscription to empty object on JSON parse failure to prevent type confusion

Author: andris9

lib/email-client/outlook-client.js

@@ -3213,7 +3213,7 @@ class OutlookClient extends BaseClient {
             try {
                 outlookSubscription = JSON.parse(outlookSubscription);
             } catch (err) {
-                // ignore, I guess?
+                outlookSubscription = {};
             }
         }
 

workers/webhooks.js

@@ -293,7 +293,7 @@ const notifyWorker = new Worker(
                     {
                         let filteredSubData = {};
                         let isPartial = false;
-                        for (let dataKey of Object.keys(job.data.data)) {
+                        for (let dataKey of Object.keys(job.data.data || {})) {
                             switch (dataKey) {
                                 case 'id':
                                 case 'uid':