plugin-event-handler

@myadmin-plugins

Adds a new Symfony GenericEvent hook handler to src/Plugin.php following the existing pattern. Use when user says 'add hook', 'new event handler', 'handle event', 'add plugin action', or needs to wire a new lifecycle event (activate, suspend, terminate, change IP, menu). Registers in getHooks() and implements the handler with category check and stopPropagation(). Do NOT use for adding procedural API functions to src/whmsonic.inc.php.