feat: Implement comprehensive promoter system with dashboard and role-based access

This commit implements a complete promoter system that allows professional users
(is_professionnal: true) to manage events with advanced analytics and controls.

## Key Features Added:

### Role-Based Access Control
- Update User#can_manage_events? to use is_professionnal field
- Add promoter? alias method for semantic clarity
- Restrict event management to professional users only

### Enhanced Navigation
- Add conditional "Créer un événement" and "Mes événements" links
- Display promoter navigation only for professional users
- Include responsive mobile navigation with appropriate icons
- Maintain clean UI for regular users

### Comprehensive Promoter Dashboard
- Revenue metrics with total earnings calculation
- Tickets sold counter across all events
- Published vs draft events statistics
- Monthly revenue trend chart (6 months)
- Recent events widget with quick management actions
- Recent orders table with customer information

### Advanced Analytics
- Real-time revenue calculations from order data
- Monthly revenue trends with visual progress bars
- Event performance metrics and status tracking
- Customer order history and transaction details

### Event Management Workflow
- Verified existing event CRUD operations are comprehensive
- Maintains easy-to-use interface for event creation/editing
- State management system (draft → published → cancelled)
- Quick action buttons for common operations

### Documentation
- Comprehensive implementation guide in docs/
- Technical details and architecture explanations
- Future enhancement recommendations
- Testing and deployment considerations

## Technical Implementation:

- Optimized database queries to prevent N+1 problems
- Proper eager loading for dashboard performance
- Responsive design with Tailwind CSS components
- Clean separation of promoter vs regular user features
- Maintainable code structure following Rails conventions

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

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

app/controllers/pages_controller.rb

@@ -39,6 +39,52 @@ class PagesController < ApplicationController
                                       .can_retry_payment
                                       .order(:expires_at)
 
+    # Promoter-specific data if user is a promoter
+    if current_user.promoter?
+      @promoter_events = current_user.events.includes(:orders, :tickets)
+                                           .order(created_at: :desc)
+                                           .limit(5)
+      
+      # Revenue metrics for promoter
+      @total_revenue = current_user.events
+                                  .joins(:orders)
+                                  .where(orders: { status: ['paid', 'completed'] })
+                                  .sum('orders.total_amount_cents') / 100.0
+      
+      @total_tickets_sold = current_user.events
+                                       .joins(:tickets)
+                                       .where(tickets: { status: 'active' })
+                                       .count
+      
+      @active_events_count = current_user.events.where(state: 'published').count
+      @draft_events_count = current_user.events.where(state: 'draft').count
+      
+      # Recent orders for promoter events
+      @recent_orders = Order.joins(:event)
+                           .where(events: { user: current_user })
+                           .where(status: ['paid', 'completed'])
+                           .includes(:event, :user, tickets: :ticket_type)
+                           .order(created_at: :desc)
+                           .limit(10)
+      
+      # Monthly revenue trend (last 6 months)
+      @monthly_revenue = (0..5).map do |months_ago|
+        start_date = months_ago.months.ago.beginning_of_month
+        end_date = months_ago.months.ago.end_of_month
+        
+        revenue = current_user.events
+                             .joins(:orders)
+                             .where(orders: { status: ['paid', 'completed'] })
+                             .where(orders: { created_at: start_date..end_date })
+                             .sum('orders.total_amount_cents') / 100.0
+        
+        {
+          month: start_date.strftime("%B %Y"),
+          revenue: revenue
+        }
+      end.reverse
+    end
+
     # Simplified upcoming events preview - only show if user has orders
     if @user_orders.any?
       ordered_event_ids = @user_orders.map(&:event).map(&:id)