diff --git a/apps/pwa/src/App.test.tsx b/apps/pwa/src/App.test.tsx
index 0acd7aa..496d4ed 100644
--- a/apps/pwa/src/App.test.tsx
+++ b/apps/pwa/src/App.test.tsx
@@ -25,8 +25,17 @@ vi.mock('./components/CalendarShell.js', () => ({
   CalendarShell: () => <div data-testid="calendar-shell">CalendarShell</div>,
 }));
 
+// SetupPage mock respects the `alreadyLocked` prop so the reverse-gate test (gap 5)
+// can distinguish the active wizard (Step 1 "Welcome to FamilySync Setup") from the
+// Surface 8 "Setup already complete" terminal surface. The real SetupPage renders
+// these two surfaces based on this exact prop — see routes/SetupPage.tsx.
 vi.mock('./routes/SetupPage.js', () => ({
-  SetupPage: () => <div data-testid="setup-page">SetupPage</div>,
+  SetupPage: ({ alreadyLocked }: { alreadyLocked?: boolean }) =>
+    alreadyLocked ? (
+      <div data-testid="setup-page">Setup already complete</div>
+    ) : (
+      <div data-testid="setup-page">Welcome to FamilySync Setup</div>
+    ),
 }));
 
 vi.mock('./components/AppNav.js', () => ({
@@ -177,6 +186,41 @@ describe('App — setup-status gate', () => {
       expect(screen.getByTestId('setup-page')).toBeInTheDocument();
     });
   });
+
+  // gap 5 (T-12-04): manually visiting /setup AFTER setup is complete must show the
+  // "Setup already complete" surface (alreadyLocked), NOT re-mount the active wizard.
+  it('renders the "already complete" surface (not the wizard) on /setup when setupComplete is true', async () => {
+    mockFetchSetupStatus.mockResolvedValue({ setupComplete: true });
+    // Navigate directly to /setup (URL-isolation pattern — beforeEach reset to /)
+    window.history.pushState({}, '', '/setup');
+
+    const queryClient = makeQueryClient();
+    renderApp(queryClient);
+
+    await waitFor(() => {
+      expect(screen.getByTestId('setup-page')).toHaveTextContent('Setup already complete');
+    });
+
+    // The active wizard's Step 1 heading must NOT render when setup is complete
+    expect(screen.queryByText('Welcome to FamilySync Setup')).toBeNull();
+    // Standalone wizard surface — no AppNav shell on /setup
+    expect(screen.queryByTestId('app-nav')).toBeNull();
+  });
+
+  // gap 5 counterpart: /setup with setupComplete false still mounts the active wizard.
+  it('renders the active wizard on /setup when setupComplete is false', async () => {
+    mockFetchSetupStatus.mockResolvedValue({ setupComplete: false });
+    window.history.pushState({}, '', '/setup');
+
+    const queryClient = makeQueryClient();
+    renderApp(queryClient);
+
+    await waitFor(() => {
+      expect(screen.getByTestId('setup-page')).toHaveTextContent('Welcome to FamilySync Setup');
+    });
+
+    expect(screen.queryByText('Setup already complete')).toBeNull();
+  });
 });
 
 describe('App — setupStatus and route presence', () => {
diff --git a/apps/pwa/src/App.tsx b/apps/pwa/src/App.tsx
index 1cf1e3f..b641ea5 100644
--- a/apps/pwa/src/App.tsx
+++ b/apps/pwa/src/App.tsx
@@ -81,11 +81,21 @@ export default function App() {
   // Fetch current user once at the app shell level so AppNav has member data on
   // ALL routes. This is the same query key (['me']) used by CalendarShell, so
   // TanStack Query deduplicates the request — no double fetch.
+  //
+  // gap 6 (mechanism (ii) — ['me'] staleness, NOT a linking gap; see SUMMARY):
+  // the first-login claim in upsertUser (auth/user.ts) preserves the same users.id,
+  // so the wizard-stored CalDAV credential stays linked → needsProviderSetup is
+  // correctly FALSE in the DB after the operator authenticates post-wizard. The bug
+  // was purely client-cache: a ['me'] entry populated BEFORE the claim (e.g. an
+  // earlier pre-auth visit) served a stale needsProviderSetup=true for up to 5
+  // minutes, so the "Set up your calendar" banner kept showing. Set staleTime 0 on
+  // the boot ['me'] query so the authenticated app shell always refetches member
+  // status on entry — needsProviderSetup then reflects the just-claimed credential.
   const meQuery = useQuery({
     queryKey: ['me'],
     queryFn: fetchMe,
     retry: false,
-    staleTime: 5 * 60 * 1000,
+    staleTime: 0,
   });
 
   // isAdmin from /api/me — used for UX gating only (D-03). Server enforces 403.
@@ -135,8 +145,26 @@ export default function App() {
   return (
     <BrowserRouter>
       <Routes>
-        {/* /setup route — standalone wizard, no AppNav/BottomTabBar shell (UI-SPEC §Routing) */}
-        <Route path="/setup" element={<SetupPage />} />
+        {/* /setup route — standalone wizard, no AppNav/BottomTabBar shell (UI-SPEC §Routing).
+            Reverse gate (gap 5, T-12-04): once setup is complete the wizard must NOT re-mount.
+            - While setupQuery is loading → render the no-flash placeholder (no wizard before
+              status resolves), mirroring the `*`-route loading gate below.
+            - setupComplete === true → render SetupPage with alreadyLocked → Surface 8
+              ("Setup already complete"), keeping the operator on /setup with a terminal surface.
+            - setupComplete === false (or undefined post-load) → active wizard, as before.
+            The backend already 423s setup mutations; this is the matching frontend reverse-gate. */}
+        <Route
+          path="/setup"
+          element={
+            setupLoading ? (
+              <div aria-hidden="true" />
+            ) : setupComplete === true ? (
+              <SetupPage alreadyLocked={true} />
+            ) : (
+              <SetupPage />
+            )
+          }
+        />
 
         {/* All other routes are gated on setup completion */}
         <Route