feat(observability): add Sentry error and performance monitoring integration

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

app/celery_app.py

@@ -1,7 +1,7 @@
 # app/celery_app.py
 
 from celery import Celery
-from celery.signals import task_failure
+from celery.signals import task_failure, worker_ready
 
 from app.config import settings
 
@@ -22,6 +22,14 @@ celery.conf.task_routes = {
 }
 
 
+@worker_ready.connect
+def init_sentry_on_worker_ready(**kwargs):
+    """Initialise Sentry SDK in the Celery worker process."""
+    from app.utils.sentry import init_sentry
+
+    init_sentry(integrations_extra=["celery"])
+
+
 @task_failure.connect
 def task_failure_handler(
     sender=None, task_id=None, exception=None, args=None, kwargs=None, traceback=None, einfo=None, **kw