Remove unused ExpandRowRecursive after #305 (#306)

PR #305 dropped the only caller of ExpandRowRecursive in
FetchGroupedPlansAsync. Delete the now-unreachable method (only
its self-recursion remained) plus stale Avalonia/SqlClient usings
in the same file.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: erikdarlingdata

src/PlanViewer.App/Controls/QueryStoreGridControl.axaml.cs

@@ -5,12 +5,10 @@
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Threading;
-using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
 using Avalonia.Interactivity;
 using Avalonia.Media;
-using Microsoft.Data.SqlClient;
 using PlanViewer.Core.Interfaces;
 using PlanViewer.Core.Models;
 using PlanViewer.App.Dialogs;
@@ -312,8 +310,6 @@ private async System.Threading.Tasks.Task FetchGroupedPlansAsync(
         LoadButton.IsEnabled = true;
         SelectToggleButton.Content = "Select All";
 
-
-
         UpdateStatusText();
         UpdateBarRatios();
 
@@ -322,29 +318,6 @@ private async System.Threading.Tasks.Task FetchGroupedPlansAsync(
             _ = FetchGroupedWaitStatsAsync(_slicerStartUtc.Value, _slicerEndUtc.Value, ct);
     }
 
-    /// <summary>
-    /// Recursively expands a row and all its children, inserting them into _filteredRows.
-    /// </summary>
-    private void ExpandRowRecursive(QueryStoreRow row)
-    {
-        if (!row.HasChildren) return;
-        row.IsExpanded = true;
-
-        var idx = _filteredRows.IndexOf(row);
-        if (idx < 0) return;
-
-        var insertAt = idx + 1;
-        foreach (var child in row.Children)
-        {
-            _filteredRows.Insert(insertAt, child);
-            insertAt++;
-        }
-
-        // Recurse into each child that has children
-        foreach (var child in row.Children)
-            ExpandRowRecursive(child);
-    }
-
     /// <summary>
     /// Fetches per-plan wait stats for all real plan IDs found in the grouped hierarchy,
     /// assigns them to leaf rows, then consolidates upward to intermediate and root rows.