Fixed relay selection - deterministic w/ fallback.

peer/on_statetick.go

@@ -61,8 +61,10 @@ func (a *App) onStateTick() {
 		}
 	}
 
-	// Ensure we have a live relay (if we're not public).
-	if !a.isPublic && (a.relay == nil || !a.relay.Up()) {
+	// Keep the active relay pinned to the lowest-IP live relay (if we're not
+	// public). switchActiveRelay is idempotent and handles failover when the
+	// current relay dies as well as failback when a lower-IP relay recovers.
+	if !a.isPublic {
 		a.switchActiveRelay()
 	}
 }