Bug: Protected Pages Show Blank Screen Instead of Redirecting to Login

[Shyam-Raghuwanshi]

Describe the bug
When visiting a protected page (e.g., control panel) without being logged in, the user sees a blank page and in volto sees settings instead of being redirected to the login page.

To Reproduce

1. Open an incognito window or log out from the site.

2. Visit a protected page like:
   https://demo.plone.org/controlpanel/site
   https://volto.demo.plone.org/controlpanel/

Observe that the page is blank instead of redirecting to the login screen.

Expected behavior
Users should be redirected to the login page when trying to access a protected page without authentication.

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[stevepiercy]

Screenshots below from a private browser window, unauthenticated. In both, the Log in link displays in the upper right.

• https://volto.demo.plone.org/controlpanel/ displays a partial list of control panels.

• https://volto.demo.plone.org/controlpanel/site displays an empty template page.