Feature Flags: Rolling Out Changes Safely

Feature flags allow you to roll out changes safely.

    Example:
    - enable a new checkout flow for 10% of users
    - test new UI in staging only
    - disable a broken feature instantly
    
    ## Simple flag storage idea
    - flags table in DB
    - cached for performance
    
    ## Example usage
    
    ```php
    if (Feature::enabled('new_checkout')) {
      return app(NewCheckoutController::class)->index();
    }
    
    return app(LegacyCheckoutController::class)->index();
    ```
    
    ## Flow
    
    ```mermaid
    flowchart LR
      A[Request] --> B[Check Feature Flag]
      B -->|On| C[New Feature]
      B -->|Off| D[Old Feature]
    ```
    
    In the next tutorial, we will add audit-grade security practices for production.