fix(ui): unfreeze the operation spinner and attribute rebind churn

Three causes behind the stuck indicator:
- OperationStatus.End did not retire the generation, so tick work posted
  while the dispatcher was blocked drained afterwards and set
  ShowIndicator back to true on a finished operation.
- The startup update check ran in Task.Run; OperationStatus writes its
  observable properties on the calling thread, so the final
  ShowIndicator=false never reached the binding.
- OperationIndicator overwrote its own DataContext from the Status
  property, which re-targeted the call-site binding. It now scopes the
  DataContext to an inner panel and collapses itself when Status is
  null; every call site switched from DataContext= to Status=.

Also gates the footer connection pill in the command body instead of
CanExecute (a disabled command greyed out the ONLINE chip), and extends
OperationTiming: pid per line, 4 MB rollover, fast successes dropped
(failures always kept), and DetailsIsland.BindAsync now carries the
selection trigger via TasksIslandViewModel.SelectFrom.

src/ClaudeDo.Ui/Views/JumpToTaskHelper.cs

@@ -18,7 +18,7 @@ internal static class JumpToTaskHelper
         s.Lists.SelectedList = item;
 
         var existing = s.Tasks.Items.FirstOrDefault(r => r.Id == taskId);
-        if (existing is not null) { s.Tasks.SelectedTask = existing; return; }
+        if (existing is not null) { s.Tasks.SelectFrom(existing, "jump-to-task"); return; }
 
         var tcs = new TaskCompletionSource<bool>();
         void OnChanged(object? _, NotifyCollectionChangedEventArgs __)
@@ -32,7 +32,7 @@ internal static class JumpToTaskHelper
         {
             await Task.WhenAny(tcs.Task, Task.Delay(5000));
             var row = s.Tasks.Items.FirstOrDefault(r => r.Id == taskId);
-            if (row is not null) s.Tasks.SelectedTask = row;
+            if (row is not null) s.Tasks.SelectFrom(row, "jump-to-task");
         }
         finally
         {