The engine sent clipboard over every transport at once, so the server always
saw the payload even with RTC/LAN up. Now the RTC and LAN transports report
their directly-reachable peers (data-channel open / TCP connected) into a shared
set, and the RTC transport records who's present from presence chirps. send()
skips the SSE relay when every present peer is directly reachable — so once P2P
is established the server only ever carries signaling/presence, never content.
Falls back to the relay whenever a present peer isn't directly reachable, or
before the direct link is up.
Also drop empty-text clipboards in the sink (were surfacing as blank "unknown"
feed rows).
Proven by examples/prefer_direct.rs: two engines link directly on the live
server; a send reaches the peer but never appears on the server bus (only
presence does).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Patrick Ecord
7ccb32bb64
