Function read_entity_string_field_ctx 

pub fn read_entity_string_field_ctx(
    store: impl AsContextMut,
    entity: Rooted<StructRef>,
    kind: EntityKind,
    field_name: &str,
) -> Result<String>

Context-based core of read_entity_string_field, split out so it is unit-testable without a Caller (tests hold a bare Store). Resolves the field’s slot from the entity layout and reads it as an $i8_array string.