Exercise the previously-untested branches of the settings category renderer:
number-field commit/clamp/unparseable-revert, text-field commit, the file
control's command button, the select raw-value fallback, scope move-to-app,
field help text, and the cross-category search empty state. Restores the
coverage floor after the D-101 facade migration shifted the ratio.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>