fix: Update views and controllers for event image display

Update all event-related view templates and controllers to properly handle and display event images throughout the application.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/views/events/index.html.erb

@@ -22,7 +22,7 @@
       <% @events.each do |event| %>
         <article class="group bg-white rounded-2xl shadow-lg hover:shadow-2xl transition-all duration-300 overflow-hidden transform hover:-translate-y-1">
           <%= link_to event_path(event.slug, event), class: "block" do %>
-            <% if event.image.attached? %>
+            <% if event.has_image? %>
               <div class="relative overflow-hidden aspect-[4/3]">
                 <%= image_tag event.event_image_variant(:medium), alt: event.name, class: "w-full h-full object-cover group-hover:scale-105 transition-transform duration-300" %>
                 <!-- Event featured badge -->