Implement ticket selection with Stimulus controller and improve code documentation

- Add ticket selection functionality to event show page using Stimulus
- Create ticket_selection_controller.js for handling ticket quantity changes
- Update ticket card component and event show view to work with Stimulus
- Add comprehensive comments to all JavaScript files for better maintainability
- Remove dependent: :destroy from event ticket_types association

app/models/event.rb

@@ -15,7 +15,7 @@ class Event < ApplicationRecord
 
   # === Relations ===
   belongs_to :user
-  has_many :ticket_types, dependent: :destroy
+  has_many :ticket_types
   has_many :tickets, through: :ticket_types
 
   # Validations for Event attributes