release-2.30.12-webos.6

Pre-release: netlink uevent hotplug monitor, replacing the 3s presence-flag poll. Instant, explicit add/remove events (no same-index reconnect blind spot), with ENOBUFS recovery and a poll fallback. Verified in the app jail on webOS 3.4 (kernel 3.10), 4 (4.4) and 10 (5.4).