fix: Let the Admin role do its work: permissions, sign-in and listings

Problem/Motivation

A member of the Admin role cannot write a feature: the Gherkin script field is closed and no role holds a step of the automated testing workflow. Anonymous visitors meet an access denied page with no way to sign in.

Steps to reproduce

1. Install Cucumber and sign in as a member of the Admin role.
2. Open /media/add/feature.
3. The Gherkin Script field is disabled, and saving fails on the workflow state.

Proposed resolution

• Grant the Admin role the Gherkin text format, the steps of the workflow and the permissions the Feature form needs. No permission that administers the site.
• Require and install Anonymous Redirect.
• Name the steps of the workflow after where they lead, and add the way back to Draft.
• The Features page asks for "access features page".
• Say when a listing is empty.
• Update functions bring installed sites to the same configuration.

Remaining tasks

• ✔ File the issue
• ➖ Merge request with a green pipeline
• ➖ Prove on a fresh install and on an updated site

User interface changes

N/A

API changes

N/A

Data model changes

The automated testing workflow changes, with an update function.

AI-Generated: Yes