UnstablePortal

- Fixed safe-mode timing: previously, post-processing was triggered in the same tick after PlayerPortalEvent, which meant that with cancel-portal-exit: false, it could be executed before the actual teleport. - Teleportation with cancel-portal-exit: true has been moved to a “plugin” cause (TeleportCause.PLUGIN) so that other plugins/anti-cheats can distinguish this teleportation more correctly. ​ - The unreliable check unstableMessage.equals(Component.empty()) has been removed: now an empty/blank message correctly disables message sending. - The platform is no longer set to “always”: previously, createPlatform() was called every time safe-mode: true, even if the player was not stuck. ​ - Added protection against teleportation to the roof of the Nether: random Y and point search are limited to a safe maximum (below the bedrock layer), so the coordinate will not go into the roof area. ​ - Improved base point selection