Two switches on every feature
A feature — every Quill, and every area of the app — has two switches, and they are not the same kind of thing.
The server's is an administrator's, in the Administration panel. Off means off everywhere: the tab goes from every client, for everybody, and the API answers 403 to anything that belongs to it. It is a statement about what this server is.
Yours is in your own settings — the terminal app's Settings (^g), and
Me on the phone. Off means the tab goes from your clients, on every
machine you sign in from, because the answer is kept with your account
rather than on the machine. It is a preference, so it hides rather than
forbids: the API still answers you, and a link straight to a hidden screen
still works. A preference that closed the door would be a mistake with no
way back from the phone you made it on.
The two only ever narrow, and the narrower one wins. A feature the server has switched off is not in your settings at all — not listed as off, not listed — because it is not a thing you can have an opinion about. Your own answer is remembered underneath it, so a feature switched off and back on by an administrator comes back as you left it, not as they found it.
What is yours follows from that. The count on the home-screen icon stops counting chat messages when you switch Chat off, because a number for a tab you have not got is a count of something you cannot go and read. And with every tab switched off the terminal app says so and points at Settings, rather than leaving a pane up that nothing points at.
Switching one off for yourself:
In the web app
Me → What your apps show you: a tick box per feature.
In the terminal app
Settings (ctrl+g) → what this app shows you: the same tick boxes.
On the command line
Not there: a hidden tab is a preference of the apps, and cm <quill> answers
whatever the server offers. The switch itself is PATCH /api/me/features/<key>
with {"enabled": false}.
Switching one off for everybody (administrators):
In the web app
Me → Administration → Quills, then the Quill's sheet: On for everybody, with who last switched it.
In the terminal app
Administration (f9) → Quills, on Server Quills: stand on the
Quill and press On/off (o). The details beside the list say who last
switched it.
On the command line
No cm command yet; it is PATCH /api/server/features/<key> with
{"enabled": false}, as an administrator.
Two endpoints, and the difference between them is the whole of the story:
/api/server/features is the server's list, readable by anybody and
switchable by an administrator; /api/me/features is the same catalogue
narrowed to you, with your answer on each, and yours to switch. A client
that draws tabs asks the second one.
From docs/MANUAL.md in the Cloudmorrow repository. Something wrong? A pull request there fixes it here.