Get Started guide says a new session ends the current one and that the group selector is on the Dashboard #1788

The "How to Get Started with ODC" guide tells new users two things the web app does not do. It says "Starting a new session will automatically end an existing session". The app refuses instead: while a session is active, the Start Session nav item is disabled, the page hides its form, and it shows "you must end the current session before completing this form again". The user has to end the session first, with the End Session button in the sidebar (or the mobile nav) or by switching group. The guide also says group managers change group "using the group selector on Dashboard" and should "confirm the selected group on Dashboard". f2114f706 (July 2026) removed the Dashboard's group dropdown and added a persistent group switcher. That switcher is in the sidebar or the top bar, depending on the instance's setting. It is shown to every user, not only group managers, and the Dashboard has no selector. A first-time user who follows the guide looks for controls that are not there.

Where

docs/en/3-guides/3.4-how-to-get-started-with-odc.mdx:49-51, :109 and :156:

The selected group controls which instruments and data you see.

Group managers use the group selector on Dashboard to change the selected group.
...
ODC allows one active session at a time. Starting a new session will automatically end an existing session.
...
- **I see the wrong instruments or data:** A group manager should confirm the selected group on Dashboard.

What the app does, at apps/web/src/hooks/useNavItems.ts:252-258:

if (ability?.can('create', 'Session')) {
  sessionItems.push({
    disabled: currentSession !== null,
    icon: CirclePlayIcon,
    label: t('layout.navLinks.startSession'),
    url: '/session/start-session'
  });
}

apps/web/src/routes/_app/session/start-session.tsx:50 renders the form only {currentSession === null && (, and :108-112 shows the "must end the current session" notice. The switcher is rendered by apps/web/src/components/Sidebar/Sidebar.tsx:44-46 and apps/web/src/components/Layout/Layout.tsx:31-33, and apps/web/src/hooks/useSwitchableGroups.ts returns groups for every user.

Reproduce

1. Sign in as a standard user who belongs to two groups, and start a session.
2. Try to start a second session for another subject, as the guide describes.
3. Look for a group selector on the Dashboard as a group manager.

Actual: Start Session is greyed out in the nav, and its page shows only the "Session Successfully Started" card. The Dashboard has no group selector; it is in the sidebar (or top bar) for both users.
Expected: the guide tells users to end the current session from the sidebar before starting another, and to switch groups with the sidebar or top-bar group switcher.

Tests

docs/ has no test runner (docs/AGENTS.md). Review the corrected text against useNavItems.ts, start-session.tsx and GroupSwitcher.tsx.

Suggested fix

Replace the session sentence with "ODC allows one active session at a time. End the current session from the sidebar before starting another; switching group also ends it." Rewrite the "Select a Group" section and the troubleshooting entry to point at the group switcher in the sidebar (or top bar). Drop "Group managers": any user with more than one group can switch.