Harden tables selection interactions

src/RolemasterDb.App/Components/Tables/TablesCanvas.razor

@@ -33,7 +33,13 @@
 
                     @if (MatchesModeFilter(cell))
                     {
-                        <div class="@GetCellCssClass(cell, displayColumn.GroupKey)" @onclick="() => SelectCell(cell)">
+                        <div
+                            class="@GetCellCssClass(cell, displayColumn.GroupKey)"
+                            role="button"
+                            tabindex="0"
+                            aria-pressed="@isSelectedCell"
+                            @onclick="() => SelectCell(cell)"
+                            @onkeydown="args => HandleCellKeyDown(args, cell)">
                             <div class="critical-table-cell-shell">
                                 <div class="critical-table-cell-actions">
                                     @if (string.Equals(CurrentMode, TablesReferenceMode.Reference, StringComparison.Ordinal))
@@ -306,5 +312,17 @@
     private bool IsSelectedCell(CriticalTableCellDetail cell) =>
         SelectedCell is not null && cell.ResultId == SelectedCell.ResultId;
 
+    private Task HandleCellKeyDown(KeyboardEventArgs args, CriticalTableCellDetail cell)
+    {
+        if (string.Equals(args.Key, "Enter", StringComparison.Ordinal) ||
+            string.Equals(args.Key, " ", StringComparison.Ordinal) ||
+            string.Equals(args.Key, "Spacebar", StringComparison.Ordinal))
+        {
+            return SelectCell(cell);
+        }
+
+        return Task.CompletedTask;
+    }
+
     private static string BuildColumnSpanStyle(int span) => $"grid-column: span {span};";
 }