fix(grid): treat bulk-edit NULL keyword as SQL NULL

apps/desktop/src/lib/dataGrid/dataGridInlineBulkEdit.ts

@@ -12,3 +12,15 @@ export function dataGridInlineBulkEditValue(event: DataGridInlineBulkEditKeyEven
   if (event.key === "Enter") return "";
   return event.key !== "Process" && Array.from(event.key).length === 1 ? event.key : undefined;
 }
+
+/**
+ * Bulk-edit dialog contract (placeholder "Value, or NULL"): empty input and the
+ * bare keyword `NULL` stage SQL NULL. Every other input is kept as typed so a
+ * text column can still receive the literal word via quoted/user-specific input
+ * outside this dialog path.
+ */
+export function bulkEditInputToSqlValue(input: string): string | null {
+  const trimmed = input.trim();
+  if (trimmed === "" || trimmed.toUpperCase() === "NULL") return null;
+  return input;
+}