💄 Enhance pricing section UI and credit badge

Improve layout and styling of pricing options and user credit badge for better visual appeal and user experience. :sparkles: Enhance generation display and sharing options Improve the index and show views by refining image handling and adding share and delete functionalities for better user interaction. :sparkles: Enhance subject_context with name attribute Update subject_context method to include subject name and adjust related code for consistency in image generation jobs and tests. :sparkles: Introduce image download functionality Add a new download_image action and update routes to allow users to download generated images in different resolutions. Update views to link to the new download paths and adjust tests accordingly. :sparkles: Update welcome email content and formatting Enhance the welcome email with improved text and HTML structure for better user engagement and clarity.