This commit updates all instances of 'base' line item type to 'flat'. It modifies the BillingIntervalSchema, the validation rules for one-time plans, and the function to get the primary line item for a plan. Furthermore, it adjusts the display and filtering of line items in the pricing table component and the plan picker component. The SQL migration script and the sample billing configuration are also updated to reflect this change.
This commit provides the addition of a new enhanced route handler functionality for Next.js utilities. The handler facilitates additional functionality, allowing more control over HTTP requests. Changes also include improved code where 'zodParseFactory' functionality moved to utils for better code reuse and organization.
