- Updated the `RejectPaymentRequestCommandHandler` to immediately suspend user configs if a payment request is rejected and no other pending subscription requests exist.
- Introduced `SuspendIfStillUnpaidAsync` method to handle the logic for suspending configs based on the user's billing status.
- Enhanced the `MarkPaymentSentCommandHandler` to protect configs during the payment confirmation process, ensuring users remain active while awaiting admin approval.
- Refactored `BillingConfigResumer` to include methods for protecting and suspending configs, improving the overall billing management flow.
- Updated tests to cover new behaviors and ensure proper functionality in various scenarios related to payment requests and config management.
- Introduced billing capabilities, allowing users to request payments for subscription periods (3/6/12 months) with admin approval via Telegram.
- Updated role management to include a `BillingEnabled` property, preventing billing for admin roles.
- Enhanced the `CreateRoleCommand` and `UpdateRoleCommand` to accept billing parameters, ensuring proper handling during role creation and updates.
- Added new endpoints for billing management and integrated billing checks into VPN config creation to enforce payment requirements.
- Updated related services, models, and tests to support the new billing features, ensuring comprehensive coverage and functionality.
- Enhanced documentation to reflect the new billing processes and role management changes.
Leonid Pershin