feat: add structured logging to BullMQ queues and workers

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/backend/src/queues/workers/mail.ts

@@ -1,11 +1,15 @@
 import { Worker } from "bullmq";
 import { redisConnectionOpts } from "../connection.js";
 import { sendVerification, sendPasswordReset } from "../../lib/email.js";
+import { logger } from "../../lib/logger.js";
+
+const log = logger.child({ component: "mail-worker" });
 
 export function startMailWorker(): Worker {
   const worker = new Worker(
     "mail",
     async (job) => {
+      log.info({ jobId: job.id, jobName: job.name }, `Processing mail job`);
       switch (job.name) {
         case "sendVerification":
           await sendVerification(job.data.email as string, job.data.token as string);
@@ -16,12 +20,13 @@ export function startMailWorker(): Worker {
         default:
           throw new Error(`Unknown mail job: ${job.name}`);
       }
+      log.info({ jobId: job.id, jobName: job.name }, `Mail job completed`);
     },
     { connection: redisConnectionOpts },
   );
 
   worker.on("failed", (job, err) => {
-    console.error(`Mail job ${job?.id} (${job?.name}) failed:`, err.message);
+    log.error({ jobId: job?.id, jobName: job?.name, err: err.message }, `Mail job failed`);
   });
 
   return worker;