Replace the non-functional 7-tap build number with a SwitchPreferenceCompat
in a new Developer category. Reads and writes
Settings.Global.DEVELOPMENT_SETTINGS_ENABLED directly; requires
WRITE_SECURE_SETTINGS (granted via platform certificate). Toggle state
re-syncs in onResume so it stays accurate if changed elsewhere.
Privileged system app that registers with Settings via
com.android.settings.action.EXTRA_SETTINGS, appearing under
the Device category. Provides an empty PreferenceScreen
ready for PawletOS-specific toggles.
