Lightyear Link

This crate defines the Link component and related abstractions for network communication. A Link represents a connection to a remote peer and handles the buffering of incoming and outgoing byte payloads. It is transport-agnostic, meaning the actual sending and receiving of bytes over a physical (or virtual) network is handled by a separate IO layer (e.g., UDP, WebTransport, Crossbeam channels).

It also includes features like:

• Link conditioning (simulating latency, jitter, packet loss) via LinkConditioner.
• Link state management (Linked, Linking, Unlinked).
• Basic link statistics (LinkStats).