Create app/storage.py

app/storage.py

@@ -0,0 +1,11 @@
+from collections import deque
+from typing import Deque, Set
+from .models import Message
+import asyncio
+from fastapi import WebSocket
+
+messages: Deque[Message] = deque(maxlen=50)
+connected_readers: Set[WebSocket] = set()
+
+# Single lock for both message list and reader set
+storage_lock = asyncio.Lock()