Function build_node_mesh 

pub fn build_node_mesh(
    identity: &NodeIdentity,
    peers: &[SocialPeer],
    bind_ip: IpAddr,
    read_timeout: Option<Duration>,
) -> Result<(SocialWebNet, Vec<PeerAddOutcome>), String>

Build a live SocialWebNet for this node, adding a tunnel for every reachable peer (active + valid WireGuard key). Inactive or keyless peers are skipped with a note. Peers whose endpoint is known are pre-pointed; the rest wait to learn it by roaming.

Returns the mesh and a per-peer outcome list. Bringing up the handshake and pumping is the caller’s job (the mesh is a passive, caller-driven state machine — see SocialWebNet::pump).