Updated the billing system's schema to change 'storeId' to a string type, and improved the cleanliness and readability of the code. Enhanced the logging system within the billing service for better tracking and debugging. In line with these changes, added corresponding error pages in the client side to handle any errors.
New README files have been added for the packages dealing with the Stripe and Lemon Squeezy billing systems. They explain the purpose of the packages and detail what environment variables need to be set for development and production.