Website Event Filter Organizer

On the public website events page, visitors now get an extra filter block in the left column called "Filter by Organizer". It lists every organizer that has events in the current results, with a badge showing how many events each one has, plus an "All Organizers" entry to clear the filter.

• Clicking an organizer reloads the events page showing only that organizer's events, and the chosen organizer name appears in the breadcrumb at the top of the page.
• The organizer filter works together with the existing date, category and location filters: when you pick a date, category or country, the organizer choice is kept, and vice versa.
• The event list is paginated in groups of 10 events, and the page links keep the selected organizer, date, category and country.

This module only changes the public website event browsing experience. It does not add new menus in the backend and does not change how events are created or managed. It relies on the standard event organizer field (organizer_id) on event.event and extends the website event controller and templates.