Add Admin Configuration to Toggle Profile Picture API Response Type (BinaryFileResponse vs Redirect)

We need to implement an admin configuration form that allows us to easily switch the response type used by the Profile Picture API endpoint between:

• BinaryFileResponse
• Plain HTTP redirect

We are currently evaluating the best approach for serving profile pictures in production. Being able to toggle between these two response strategies—without requiring code changes or deployments—will allow us to efficiently compare performance and behavior between the two solutions.