The Chat UI Tests CI run failed at "nav 'New Chat' not found": the
get_by_role("button", name="New Chat") path doesn't always match
because SidebarMenuButton wraps the visible label in a <span> that
the accessibility-name calculation can lose track of when the sidebar
is in a collapsed/icon-only state.
Try, in order:
1. [data-sidebar="menu-button"]:has-text("New Chat") -- the
shadcn-ui SidebarMenuButton renders with this attribute.
2. role=button, name=re.compile(...) -- the existing path.
3. button:has-text("New Chat") -- last-resort.
The first locator works regardless of sidebar collapse state because
data-sidebar="menu-button" is part of the component contract, not
the visual layout.