Function first_party_generators 

pub fn first_party_generators(
    command_registry: CommandRegistryHandle,
    config: Arc<ConfigRegistry>,
    keybinding_reverse: Arc<dyn KeymapReverseLookup>,
    grep_highlighter: Option<Arc<dyn GrepPreviewHighlighter>>,
) -> Vec<Arc<dyn PickerSourceGenerator>>

Convenience: build the first-party source generators as Arc<dyn PickerSourceGenerator> ready to register against a PickerRegistry. Used by App::new (and a future host- owned Editor::boot) to boot the registry. Sources that need App-wide state captured at construction (e.g. CommandsSource -> CommandRegistry, GrepSource -> ConfigRegistry) take the relevant Arc here so the trait surface stays state-handle-free.