fix: podcast tasks for Windows compatibility

- Added WindowsProactorEventLoopPolicy for better async subprocess support on Windows.
- Ensured proper cleanup of the event loop after task execution.
- Removed redundant asyncio import from the generate_chat_podcast_task function.

surfsense_backend/app/tasks/celery_tasks/podcast_tasks.py

@@ -1,6 +1,8 @@
 """Celery tasks for podcast generation."""
 
+import asyncio
 import logging
+import sys
 
 from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
 from sqlalchemy.pool import NullPool
@@ -11,6 +13,14 @@ from app.tasks.podcast_tasks import generate_chat_podcast
 
 logger = logging.getLogger(__name__)
 
+if sys.platform.startswith("win"):
+    try:
+        asyncio.set_event_loop_policy(asyncio.WindowsProactorEventLoopPolicy())
+    except AttributeError:
+        logger.warning(
+            "WindowsProactorEventLoopPolicy is unavailable; async subprocess support may fail."
+        )
+
 
 def get_celery_session_maker():
     """
@@ -39,8 +49,6 @@ def generate_chat_podcast_task(
         podcast_title: Title for the podcast
         user_id: ID of the user
     """
-    import asyncio
-
     loop = asyncio.new_event_loop()
     asyncio.set_event_loop(loop)
 
@@ -48,7 +56,9 @@ def generate_chat_podcast_task(
         loop.run_until_complete(
             _generate_chat_podcast(chat_id, search_space_id, podcast_title, user_id)
         )
+        loop.run_until_complete(loop.shutdown_asyncgens())
     finally:
+        asyncio.set_event_loop(None)
         loop.close()