Notes is optional when editing transaction

MoneyMap/Pages/EditTransaction.cshtml.cs

@@ -84,6 +84,12 @@ namespace MoneyMap.Pages
 
         public async Task<IActionResult> OnPostAsync()
         {
+            // Remove Notes from model state validation if it's empty
+            if (string.IsNullOrWhiteSpace(Transaction.Notes))
+            {
+                ModelState.Remove("Transaction.Notes");
+            }
+
             if (!ModelState.IsValid)
             {
                 await LoadDataAsync();