use crate::;
/// Marker trait that selects between read-write and read-only storage.
///
/// Composite types use `M::Stored<V>` for stored vec fields.
/// When `M = Rw`, the field is `V` itself (identity) with full write access.
/// When `M = Ro`, the field is `V::ReadOnly` — a lean read-only clone (~40-48 bytes).
/// Read-write mode. `Stored<V>` is the identity — the full read-write vec.
;
/// Read-only mode. `Stored<V>` is `V::ReadOnly` — a lean clone for disk reads.
;