Challenge not found error when managing a hidden/challenge with release time

[zolbooo]

What happened?

In admin panel, when managing a hidden or a challenge with release time there is an error toast showing up: The challenge could not be found.

This is due /solves API returning 404.

Steps to reproduce

1. Create a challenge, make it hidden
2. Open the challenge in admin panel

Version

535bb34

Affected component

Web frontend

How is it deployed?

Bundled container (compose.yml)

Relevant logs

<img width="637" height="88" alt="Image" src="https://github.com/user-attachments/assets/2d337ed5-f2da-45ce-9df1-8b1312310d08" />