- Consolidated import statements in `updateStripeSub.ts` and `invoiceRouter.ts`.
- Removed unused `handleDeleteEntity_old.ts` and `getAttachPreview.ts` files.
- Updated entity handling in `entitledRouter.ts` and `handleProductCheck.ts` for better null safety.
- Adjusted parameters in various functions to ensure consistency and clarity.
- Introduced default configuration in `getAttachConfig.ts` for better handling of attach parameters.
- Enhanced proration logic in `priceUtils.ts` and related files for improved billing accuracy.
