- Refactored payment method validation to check against available methods.
- Changed payment method types from "zfb" to "alipay" and "wx" to "wxpay" for consistency.
- Updated the purchase request to use the validated payment method directly.
- Added a new `setting` package to replace the `constant` package for configuration management, improving code organization and clarity.
- Moved various configuration variables such as `ServerAddress`, `PayAddress`, and `SensitiveWords` to the new `setting` package.
- Updated references throughout the codebase to use the new `setting` package, ensuring consistent access to configuration values.
- Introduced new files for managing chat settings and midjourney settings, enhancing modularity and maintainability of the code.
