feat(infrastructure): use celery worker

backend/app/core/queue.py

@@ -1,28 +1,6 @@
-# Route email jobs via Celery instead of raw RabbitMQ publishing
-# Ensure Celery app is initialized so producers use correct broker credentials.
-# Import has side effects (sets Celery default app), safe to keep at module level.
 import app.celery_app  # noqa: F401
-
-# Use a lazy proxy so _send_email_task is never None, even if Celery modules
-# are not yet importable at import time (e.g., different working dir during startup).
-class _LazySendTask:
-    def delay(self, to: str, subject: str, body: str):  # type: ignore[no-untyped-def]
-        # Late import on first use
-        from app.workers.celery_tasks import send_email_fields as _send  # type: ignore
-        return _send.delay(to, subject, body)
-
-
-try:
-    # Try eager import for normal operation
-    from app.workers.celery_tasks import send_email_fields as _send_email_task  # type: ignore
-except ImportError:  # pragma: no cover - fallback lazy import proxy
-    _send_email_task = _LazySendTask()  # type: ignore
+from app.workers.celery_tasks import send_email
 
 
 def enqueue_email(to: str, subject: str, body: str) -> None:
-    """Enqueue an email job using Celery.
-
-    Keeps the same public API as before.
-    """
-    _send_email_task.delay(to, subject, body)
-
+    send_email.delay(to, subject, body)