Update Broadcast button: diff before push, offline=local only, live=API; Go Live empty-field prompt

ViewModels/MainViewModel.cs

@@ -1565,7 +1565,8 @@ public class MainViewModel : ViewModelBase
         BroadcastForm = new Services.LiveBroadcastFormViewModel(
             () => _layoutStore,
             () => _youtubeStream,
-            () => CurrentBroadcastId);
+            () => CurrentBroadcastId,
+            () => IsLive);
 
         // Restore the last picked mic so the mixer's first capture attaches to
         // the same, already-vetted device (green dot) or reports it missing
@@ -2961,6 +2962,13 @@ public class MainViewModel : ViewModelBase
             AppLog.Write($"Broadcast created: {_currentBroadcastId}");
             OnPropertyChanged(nameof(CurrentBroadcastId));
 
+            if (string.IsNullOrWhiteSpace(StreamTitle) && string.IsNullOrWhiteSpace(StreamDescription))
+            {
+                BroadcastForm.IsDrawerOpen = true;
+                _notifications.Warning("Complete your broadcast details",
+                    "Your title and description are empty — fill them in from the Text panel on the right.");
+            }
+
             // Start chat polling (TASK 9.4): fetch the liveChatId from the broadcast's
             // contentDetails, then start the poll loop. Chat is non-fatal — if it fails,
             // the stream continues without on-panel chat.