台账分解，父项，限制表达式输入

app/public/js/ledger.js

@@ -98,7 +98,7 @@ $(document).ready(function() {
                 const data = SpreadJsObj.getSelectObject(sheet);
                 if (data) {
                     $('#bills-expr').val(data[col.field]).attr('field', col.field).attr('org', data[col.field])
-                        .attr('readOnly', readOnly || cell.locked());
+                        .attr('readOnly', readOnly || cell.locked() || (data.children && data.children.length > 0);
                 } else {
                     $('#bills-expr').val('').attr('readOnly', true);
                 }