fix(relay): forward MediaPathReport across federation

MediaPathReport was only delivered via local signal_hub, so calls
between peers on different relays always hit peer_report_timeout
and fell back to relay — even when direct P2P worked perfectly.

Fix: check peer_relay_fp in call_registry (same pattern as
DirectCallAnswer). If the peer is on a remote relay, wrap in
FederatedSignalForward and send via federation link. Also fix
the cross-relay dispatcher to deliver to BOTH caller and callee
(not just caller), since the report can come from either side.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/build.sh

@@ -73,7 +73,7 @@ if [ "$USE_ALT" = "1" ]; then
     GIT_ORIGIN="ssh://git@git.tbs.amn.gg:2222/manawenuz/wzp.git"
     # Alt server uploads directly (no .env file)
     UPLOAD_MODE="direct"
-    PASTE_URL="http://paste.tbs.amn.gg"
+    PASTE_URL="https://paste.tbs.manko.yoga"
     PASTE_AUTH="X2j6szIQaoJGaxZjLkpl3A8IX9/mTkDgdhhgyYFcpaU="
 else
     SERVER_TAG="PRI"