Function check_proposals_enabled 

pub fn check_proposals_enabled(extensions: &Extensions<GroupContext>) -> bool

Check if the given extensions belong to a migrated group.

“Migrated” means the bootstrap commit completed: the [ExtensionType::AppDataDictionary] group-context extension is present and its dict contains a COMPONENT_REGISTRY entry. This is also the canonical predicate used by [crate::groups::app_data::is_migrated_extensions]; the two converge so the rest of the codebase can use one name where the proposal-by-reference flow is the question and another where the dict-source-of-truth migration is the question.