Turn the relay into a rendezvous-only swarm: everyone sends and receives

Peers join a room and the relay just broadcasts membership (id + dialable
address); peers then connect to each other directly, PAKE-handshake per
link using the room codephrase, and exchange 1MB chunks. Resume reuses
croc's zero-block scan to detect already-received chunks, whole-file hash
verifies completion, and every peer keeps reseeding what it has to others
until stopped (--one-time restores exit-on-complete for a quick fetch).

src/tcp/defaults.go

@@ -1,9 +1,5 @@
 package tcp
 
-import "time"
-
 const (
-	DEFAULT_LOG_LEVEL             = "debug"
-	DEFAULT_ROOM_CLEANUP_INTERVAL = 10 * time.Minute
-	DEFAULT_ROOM_TTL              = 3 * time.Hour
+	DEFAULT_LOG_LEVEL = "debug"
 )