getCustomSettingKeys

Returns the list of custom setting keys with their display labels and current values.

The AA settings screen uses this to add custom toggle rows below the built-in settings. Each entry is a triple of (key, displayLabel, currentValue).

Default implementation returns empty list (no custom settings).

Example

override fun getCustomSettingKeys() = listOf(
    CustomSettingDescriptor("eco_mode", "Eco Mode", preferences.isEcoModeEnabled()),
    CustomSettingDescriptor("scenic_route", "Prefer Scenic Routes", preferences.isScenicEnabled())
)