fix usb device update behavior

src/auracast/server/multicast_frontend.py

@@ -66,7 +66,12 @@ if audio_mode in ["Webapp", "USB"]:
         if default_input not in input_options:
             default_input = input_options[0]
 
-        selected_option = st.selectbox("Input Device", input_options, index=input_options.index(default_input))
+        col1, col2 = st.columns([3, 1], vertical_alignment="bottom")
+        with col1:
+            selected_option = st.selectbox("Input Device", input_options, index=input_options.index(default_input))
+        with col2:
+            if st.button("Refresh"):
+                st.rerun()
         # We send only the numeric/card identifier (before :) or 'default'
         input_device = selected_option.split(":", 1)[0] if ":" in selected_option else selected_option
     else:
@@ -76,23 +81,22 @@ if audio_mode in ["Webapp", "USB"]:
 
     if stop_stream:
         try:
-            r = requests.post(f"{BACKEND_URL}/stop_audio")
-            if r.status_code == 200:
+            r = requests.post(f"{BACKEND_URL}/stop_audio").json()
+            if r['was_running']:
                 st.success("Stream Stopped!")
             else:
-                st.error(f"Failed to stop: {r.text}")
+                st.success("Stream was not running.")
         except Exception as e:
             st.error(f"Error: {e}")
 
     if start_stream:
         # Always send stop to ensure backend is in a clean state, regardless of current status
-        try:
-            requests.post(f"{BACKEND_URL}/stop_audio", timeout=5)
-        except Exception:
-            # Ignore connection or 500 errors – backend may not be running yet
-            pass
+        r = requests.post(f"{BACKEND_URL}/stop_audio").json()
+        if r['was_running']:
+            st.success("Stream Stopped!")
+
         # Small pause lets backend fully release audio devices before re-init
-        import time; time.sleep(0.7)
+        import time; time.sleep(1)
         # Prepare config using the model (do NOT send qos_config, only relevant fields)
         q = quality_map[quality]
         config = auracast_config.AuracastConfigGroup(