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/controllers/promoter/events_controller.rb

@@ -45,6 +45,8 @@ class Promoter::EventsController < ApplicationController
     if @event.update(event_params)
       redirect_to promoter_event_path(@event), notice: "Event mis à jour avec succès!"
     else
+      # If validation fails and a new image was attached, purge it
+      @event.image.purge if @event.image.attached? && @event.changed.include?('image')
       render :edit, status: :unprocessable_entity
     end
   end