admin: reclaim the desktop header, move pause and log out to the sidebar

the header row survives only on narrow screens; on desktop its lone occupant, log out, joins pause in the sidebar footer, both full width. pause leaves the query detail page's related actions, where a global control had no business, and its hand-rolled duration dropdown becomes a react-aria menu with real keyboard navigation, dismissal and positioning.

admin/src/shell/AppShell.tsx

@@ -110,6 +110,17 @@ const styles = stylex.create({
 		alignItems: "center",
 		gap: "0.5rem",
 	},
+	/**
+	 * In a 14rem column the button and its error stack, so the button spans the
+	 * sidebar and matches the Pause trigger below it.
+	 */
+	sidebarLogout: {
+		flexDirection: "column",
+		alignItems: "stretch",
+		gap: "0.25rem",
+		paddingInline: "1rem",
+		paddingTop: "0.75rem",
+	},
 	shell: {
 		minHeight: "100dvh",
 		height: { default: null, [WIDE]: "100dvh" },
@@ -147,8 +158,9 @@ const styles = stylex.create({
 		minWidth: { default: null, [WIDE]: 0 },
 		flexDirection: "column",
 	},
+	/** Narrow only: on WIDE the sidebar carries everything this row held. */
 	header: {
-		display: "flex",
+		display: { default: "flex", [WIDE]: "none" },
 		alignItems: "center",
 		gap: "0.75rem",
 		borderBottomWidth: 1,
@@ -284,13 +296,13 @@ function VersionFooter() {
 	);
 }
 
-function LogoutButton() {
+function LogoutButton({ style }: { style?: stylex.StyleXStyles }) {
 	const { authRequired, logout } = useAuth();
 	const navigate = useNavigate();
 	const [error, setError] = useState<unknown>(null);
 	if (authRequired !== true) return null;
 	return (
-		<div {...stylex.props(styles.logoutRow)}>
+		<div {...stylex.props(styles.logoutRow, style)}>
 			<button
 				type="button"
 				onClick={() => {
@@ -318,6 +330,7 @@ export default function AppShell() {
 				<nav aria-label="Main" {...stylex.props(styles.sidebarNav)}>
 					<NavLinks />
 				</nav>
+				<LogoutButton style={styles.sidebarLogout} />
 				<SidebarFooter />
 			</aside>
 			<div {...stylex.props(styles.column)}>