Assistant commands/keybinds should be disabled when agent is disabled

[injust]

Reproduction steps

1. Disable the agent, i.e.

{
    "agent": { "enabled": false }
}

2. Search the command palette for assistant
3. Try to rebind ctrl-enter in some global context like Workspace or Pane, e.g.

{
    {
        "context": "Pane",
        "use_key_equivalents": true,
        "bindings": { "ctrl-enter": "workspace::ToggleZoom" }
    }
}

Current vs. Expected behavior

When the agent is disabled, assistant commands still appear in the command palette, unlike agent commands.

When you try to rebind ctrl-enter, it doesn't work until you change the context to also rebind in 2 specific scenarios (!ContextEditor > Editor && mode == full and Terminal) where default keybinds exist for the assistant. So you end up with this:

{
    {
        "context": "Pane || (!ContextEditor > Editor && mode == full) || Terminal",
        "use_key_equivalents": true,
        "bindings": { "ctrl-enter": "workspace::ToggleZoom" }
    }
}

This is not a great experience for customizing keybinds as it requires digging into the default keybinds or the keyboard context view. Ideally, the default assistant keybinds would be removed entirely when the agent is disabled.

Zed version and system specs

Zed: v0.222.4+stable.147.b385025df963c9e8c3f74cc4dadb1c4b29b3c6f0 (Zed)
OS: macOS 15.7.3
Memory: 16 GiB
Architecture: x86_64

[injust]

Related to #7121 and #31346

[yeskunall]

@injust looks like we might have missed some actions in #42579. Not re-opening #31346, so I’ll keep this open instead. Thanks for the report!