chore(.gitignore): exclude local setup-direct-mode.sh operator helper

Operator helper at the repo root (`./setup-direct-mode.sh`) that
pushes the committed direct-mode YAML templates onto the mini2 / nuc
runner hosts, opens an editor to fill placeholders, writes
``LG_DIRECT_ENV`` into ``~/actions-runner/.env``, and restarts the
runner service.  Intentionally kept local — it just runs the steps
documented in ``doc/source/developer/hardware_ci.rst`` (Direct-mode
YAML templates section) with less typing — so the ignore is narrow
to the exact filename.

Author: tfcollins

.gitignore

@@ -137,3 +137,6 @@ test/hw/output/
 lg_*
 # Allow committed redacted templates in the developer docs samples dir.
 !doc/source/developer/samples/lg_*.yaml.example
+
+# One-off local operator helper, never tracked.
+/setup-direct-mode.sh