feat: Implement comprehensive event management system for promoters

This commit adds a complete event management interface allowing promoters to 
create, edit, and manage their events with full CRUD operations.

## Backend Features
- New Promoter::EventsController with full CRUD operations
- Event state management (draft, published, canceled, sold_out)
- User authorization system with can_manage_events? method
- Proper scoping to ensure users only see their own events

## Frontend Features  
- Modern responsive UI with Tailwind CSS styling
- Event listing with status indicators and quick actions
- Comprehensive event creation and editing forms
- Detailed event show page with metrics and management options
- Integration with main dashboard via promoter action buttons

## JavaScript Improvements
- Refactored inline JavaScript to dedicated Stimulus controller
- Auto-slug generation from event names with proper sanitization
- Improved code organization following Rails conventions

## Routes & Navigation
- Namespaced promoter routes under /promoter/
- RESTful endpoints with state management actions
- Proper breadcrumb navigation and user flow

## Files Added/Modified
- app/controllers/promoter/events_controller.rb (new)
- app/javascript/controllers/event_form_controller.js (new) 
- app/views/promoter/events/*.html.erb (4 new view files)
- app/models/user.rb (added authorization methods)
- app/views/pages/dashboard.html.erb (added promoter buttons)
- config/routes.rb (added promoter namespace)
- app/javascript/controllers/index.js (registered new controller)

🎯 Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

app/controllers/promoter/events_controller.rb

@@ -0,0 +1,117 @@
+# Promoter Events Controller
+#
+# Handles event management for promoters (event organizers)
+# Allows promoters to create, edit, delete and manage their events
+class Promoter::EventsController < ApplicationController
+  before_action :authenticate_user!
+  before_action :ensure_can_manage_events!
+  before_action :set_event, only: [:show, :edit, :update, :destroy, :publish, :unpublish, :cancel, :mark_sold_out]
+
+  # Display all events for the current promoter
+  def index
+    @events = current_user.events.order(created_at: :desc).page(params[:page]).per(10)
+  end
+
+  # Display a specific event for the promoter
+  def show
+    # Event is set by set_event callback
+  end
+
+  # Show form to create a new event
+  def new
+    @event = current_user.events.build
+  end
+
+  # Create a new event
+  def create
+    @event = current_user.events.build(event_params)
+    
+    if @event.save
+      redirect_to promoter_event_path(@event), notice: 'Event créé avec succès!'
+    else
+      render :new, status: :unprocessable_entity
+    end
+  end
+
+  # Show form to edit an existing event
+  def edit
+    # Event is set by set_event callback
+  end
+
+  # Update an existing event
+  def update
+    if @event.update(event_params)
+      redirect_to promoter_event_path(@event), notice: 'Event mis à jour avec succès!'
+    else
+      render :edit, status: :unprocessable_entity
+    end
+  end
+
+  # Delete an event
+  def destroy
+    @event.destroy
+    redirect_to promoter_events_path, notice: 'Event supprimé avec succès!'
+  end
+
+  # Publish an event (make it visible to public)
+  def publish
+    if @event.draft?
+      @event.update(state: :published)
+      redirect_to promoter_event_path(@event), notice: 'Event publié avec succès!'
+    else
+      redirect_to promoter_event_path(@event), alert: 'Cet event ne peut pas être publié.'
+    end
+  end
+
+  # Unpublish an event (make it draft)
+  def unpublish
+    if @event.published?
+      @event.update(state: :draft)
+      redirect_to promoter_event_path(@event), notice: 'Event dépublié avec succès!'
+    else
+      redirect_to promoter_event_path(@event), alert: 'Cet event ne peut pas être dépublié.'
+    end
+  end
+
+  # Cancel an event
+  def cancel
+    if @event.published?
+      @event.update(state: :canceled)
+      redirect_to promoter_event_path(@event), notice: 'Event annulé avec succès!'
+    else
+      redirect_to promoter_event_path(@event), alert: 'Cet event ne peut pas être annulé.'
+    end
+  end
+
+  # Mark event as sold out
+  def mark_sold_out
+    if @event.published?
+      @event.update(state: :sold_out)
+      redirect_to promoter_event_path(@event), notice: 'Event marqué comme complet!'
+    else
+      redirect_to promoter_event_path(@event), alert: 'Cet event ne peut pas être marqué comme complet.'
+    end
+  end
+
+  private
+
+  def ensure_can_manage_events!
+    unless current_user.can_manage_events?
+      redirect_to dashboard_path, alert: 'Vous n\'avez pas les permissions nécessaires pour gérer des événements.'
+    end
+  end
+
+  def set_event
+    @event = current_user.events.find(params[:id])
+  rescue ActiveRecord::RecordNotFound
+    redirect_to promoter_events_path, alert: 'Event non trouvé ou vous n\'avez pas accès à cet event.'
+  end
+
+  def event_params
+    params.require(:event).permit(
+      :name, :slug, :description, :image,
+      :venue_name, :venue_address, :latitude, :longitude,
+      :start_time, :end_time, :featured
+    )
+  end
+end