update docker files and logging for webui operation

src/auracast/server/multicast_frontend.py

@@ -1,5 +1,5 @@
 # frontend/app.py
-from itertools import filterfalse
+import os
 import streamlit as st
 import requests
 from auracast import auracast_config
@@ -240,6 +240,6 @@ else:
     #     st.error("Could not fetch advertised streams.")
 
 log.basicConfig(
-    level=log.DEBUG,
+    level=os.environ.get('LOG_LEVEL', log.DEBUG),
     format='%(module)s.py:%(lineno)d %(levelname)s: %(message)s'
 )