fix(frontend): hide logout outside local auth

frontend/src/shell/AppShell.tsx

@@ -36,7 +36,11 @@ import { useEffect, useMemo, useRef, useState } from "react";
 import type { CSSProperties } from "react";
 import { captureAuthOperation, isAuthOperationCurrent, StaleAuthOperationError, type AuthOperationGuard } from "../auth/authOperation";
 
-export function AppShell() {
+interface AppShellProps {
+  canLogout: boolean;
+}
+
+export function AppShell({ canLogout }: AppShellProps) {
   const authenticatedUser = useAuthUser();
   const [panelSession, setPanelSession] = useState<SessionSummary | null>(null);
   const {
@@ -717,7 +721,11 @@ export function AppShell() {
               <span className="min-w-0 truncate text-xs text-muted-foreground" title={authenticatedUser.displayName ?? authenticatedUser.subject}>
                 {authenticatedUser.displayName ?? authenticatedUser.subject}
               </span>
-              <Button variant="ghost" size="xs" onClick={() => { void signOut().catch(() => undefined); }}>Log out</Button>
+              {canLogout && (
+                <Button variant="ghost" size="xs" onClick={() => { void signOut().catch(() => undefined); }}>
+                  Log out
+                </Button>
+              )}
             </div>
           )}
         </div>