A mutable byte buffer with Arc-based reference counting.
Send but not Sync - can be moved between threads but not shared.
Pool-attached buffers are returned to the pool on drop.
Fixed-size byte buffer backed by a [u8; N] stack array.
Implements ByteBuffer so it can be passed wherever a byte buffer is expected.
Unlike StaticByteBuffer, no heap allocation occurs.
Immutable owned byte buffer with Arc-based sharing.
Send + Sync - can be safely shared across threads.
Used for cryptographic keys and other immutable data.
Immutable byte buffer trait for read-only access to buffer data.
Implemented by both OwnedByteBuffer (immutable, Send+Sync) and ManagedByteBuffer (mutable, Send).