[Bug] Custom domain for status page is broken

**Describe the bug**
The custom domain feature does not work anymore since 3.10
When accessing a configured domain it does not show the linked status page anymore. Instead we are redirected to login page as if it simply did not exist.

**To Reproduce**
Steps to reproduce the behavior:
1. Create a status page
2. Add custom domain name for status page (status.example.com)
3. Go to public url (status.example.com)
4. Get redirected to login page

**Expected behavior**
Status page should show up when accessing with custom domain name.

**Desktop (please complete the following information):**
- Browser Any
- Version 3.10.0

Start by reproducing the custom-domain flow described in the issue with Checkmate 3.10.0, then trace the status-page routing and authentication path for a configured domain. Done means visiting status.example.com displays its linked public status page instead of redirecting to login.

Written by the indexing model from the issue text.