Refactor Duplicate Payment Route Logic in Server.ts

[Nathydre]

Files to modify : backend/src/server.ts Acceptance Criteria :

• Extract shared payment route logic into a reusable function
• Ensure all versions (v1, v2, legacy) use this function
• Maintain current functionality and API response format
• All tests pass after refactoring Why Important : Reduces code duplication, improves maintainability

[Benalex8797]

hi maintainer, i have reviewed the code and i believe i can deliver a solid solution to this issue.

[Menjay7]

Hi! I came across this issue and would love to work on it. I have experience with similar tasks and I'm confident I can investigate, implement a clean solution, and thoroughly test it before submitting a PR. If the issue is still open, I would appreciate it if you could assign it to me. Thank you!

[grantfox-oss]

🦊 GrantFox — @Benalex8797 has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #271)
2. Your PR will be reviewed by the nathydre21 maintainers

Good luck! Track your progress on GrantFox.