UdpServer now serves many concurrent peers on one socket (removes v1's
"one peer per accept" limitation). PeerSocket becomes an enum:
ConnectedClient (client side, unchanged behavior) vs SharedServer (server
side, channel-fed inbox). A master loop reads the shared socket and
routes datagrams to the right per-peer inbox by source address; an
unknown peer's first TYPE_HS datagram spawns a new handshake task that,
on success, hands the established UdpConnection to accept(). Cleanup is
lazy via mpsc::Closed — handshake failures and connection drops self-
evict from the map. A small Arc<MasterTask> keeps the loop alive for the
lifetime of UdpServer OR any spawned UdpConnection, so existing single-
client tests (which move UdpServer into an accept task) still pass.
ReliableHsAdapter and run_reliable_handshake are unchanged. UdpClient
API unchanged. Added 3 tests: two concurrent clients with cross-talk
isolation, bad-CA client doesn't block legitimate ones, dropped peer
doesn't block others. Workspace: 117 tests green, clippy/fmt clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
xah30