Sync admin UI config: compact Gin layout density, hidden nav logo

These had been changed interactively in the admin UI (Gin layout
density -> small, Navigation logo -> hidden) but the exported config
in config/sync had drifted out of sync with the active config -- this
just catches it up.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

config/sync/gin.settings.yml

@@ -20,7 +20,7 @@ secondary_toolbar_frontend: true
 high_contrast_mode: false
 accent_color: ''
 focus_color: ''
-layout_density: default
+layout_density: small
 show_description_toggle: false
 show_user_theme_settings: false
 sticky_action_buttons: false