Fix Stage 0 bootstrap and startup regression

Task 0.1: Create database parent directory before connecting
- main.py _lifespan now calls Path(database_path).parent.mkdir(parents=True,
  exist_ok=True) before aiosqlite.connect() so the app starts cleanly on
  a fresh Docker volume with a nested database path.

Task 0.2: SetupRedirectMiddleware redirects when db is None
- Guard now reads: if db is None or not is_setup_complete(db)
  A missing database (startup still in progress) is treated as setup not
  complete instead of silently allowing all API routes through.

Task 0.3: SetupGuard redirects to /setup on API failure
- .catch() handler now sets status to 'pending' instead of 'done'.
  A crashed backend cannot serve protected routes; conservative fallback
  is to redirect to /setup.

Task 0.4: SetupPage shows spinner while checking setup status
- Added 'checking' boolean state; full-screen Spinner is rendered until
  getSetupStatus() resolves, preventing form flash before redirect.
- Added console.warn in catch block; cleanup return added to useEffect.

Also: remove unused type: ignore[call-arg] from config.py.

Tests: 18 backend tests pass; 117 frontend tests pass.

frontend/src/components/SetupGuard.tsx

@@ -33,9 +33,9 @@ export function SetupGuard({ children }: SetupGuardProps): React.JSX.Element {
         if (!cancelled) setStatus(res.completed ? "done" : "pending");
       })
       .catch((): void => {
-        // If the check fails, optimistically allow through — the backend will
-        // redirect API calls to /api/setup anyway.
-        if (!cancelled) setStatus("done");
+        // A failed check conservatively redirects to /setup — a crashed
+        // backend cannot serve protected routes anyway.
+        if (!cancelled) setStatus("pending");
       });
     return (): void => {
       cancelled = true;

frontend/src/components/__tests__/SetupGuard.test.tsx

@@ -0,0 +1,77 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, waitFor } from "@testing-library/react";
+import { MemoryRouter, Routes, Route } from "react-router-dom";
+import { FluentProvider, webLightTheme } from "@fluentui/react-components";
+import { SetupGuard } from "../SetupGuard";
+
+// Mock the setup API module so tests never hit a real network.
+vi.mock("../../api/setup", () => ({
+  getSetupStatus: vi.fn(),
+}));
+
+import { getSetupStatus } from "../../api/setup";
+
+const mockedGetSetupStatus = vi.mocked(getSetupStatus);
+
+function renderGuard() {
+  return render(
+    <FluentProvider theme={webLightTheme}>
+      <MemoryRouter initialEntries={["/dashboard"]}>
+        <Routes>
+          <Route
+            path="/dashboard"
+            element={
+              <SetupGuard>
+                <div data-testid="protected-content">Protected</div>
+              </SetupGuard>
+            }
+          />
+          <Route
+            path="/setup"
+            element={<div data-testid="setup-page">Setup Page</div>}
+          />
+        </Routes>
+      </MemoryRouter>
+    </FluentProvider>,
+  );
+}
+
+describe("SetupGuard", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("shows a spinner while the setup status is loading", () => {
+    // getSetupStatus resolves eventually — spinner should show immediately.
+    mockedGetSetupStatus.mockReturnValue(new Promise(() => {}));
+    renderGuard();
+    expect(screen.getByRole("progressbar")).toBeInTheDocument();
+  });
+
+  it("renders children when setup is complete", async () => {
+    mockedGetSetupStatus.mockResolvedValue({ completed: true });
+    renderGuard();
+    await waitFor(() => {
+      expect(screen.getByTestId("protected-content")).toBeInTheDocument();
+    });
+  });
+
+  it("redirects to /setup when setup is not complete", async () => {
+    mockedGetSetupStatus.mockResolvedValue({ completed: false });
+    renderGuard();
+    await waitFor(() => {
+      expect(screen.getByTestId("setup-page")).toBeInTheDocument();
+    });
+    expect(screen.queryByTestId("protected-content")).not.toBeInTheDocument();
+  });
+
+  it("redirects to /setup when the API call fails", async () => {
+    // Task 0.3: a failed check must redirect to /setup, not allow through.
+    mockedGetSetupStatus.mockRejectedValue(new Error("Network error"));
+    renderGuard();
+    await waitFor(() => {
+      expect(screen.getByTestId("setup-page")).toBeInTheDocument();
+    });
+    expect(screen.queryByTestId("protected-content")).not.toBeInTheDocument();
+  });
+});

frontend/src/pages/SetupPage.tsx

@@ -101,20 +101,36 @@ export function SetupPage(): React.JSX.Element {
   const styles = useStyles();
   const navigate = useNavigate();
 
+  const [checking, setChecking] = useState(true);
   const [values, setValues] = useState<FormValues>(DEFAULT_VALUES);
   const [errors, setErrors] = useState<Partial<Record<keyof FormValues, string>>>({});
   const [apiError, setApiError] = useState<string | null>(null);
   const [submitting, setSubmitting] = useState(false);
 
   // Redirect to /login if setup has already been completed.
+  // Show a full-screen spinner while the check is in flight to prevent
+  // the form from flashing before the redirect fires.
   useEffect(() => {
+    let cancelled = false;
     getSetupStatus()
       .then((res) => {
-        if (res.completed) navigate("/login", { replace: true });
+        if (!cancelled) {
+          if (res.completed) {
+            navigate("/login", { replace: true });
+          } else {
+            setChecking(false);
+          }
+        }
       })
       .catch(() => {
-        /* ignore — stay on setup page */
+        // Failed check: the backend may still be starting up. Stay on this
+        // page so the user can attempt setup once the backend is ready.
+        console.warn("SetupPage: setup status check failed — rendering setup form");
+        if (!cancelled) setChecking(false);
       });
+    return (): void => {
+      cancelled = true;
+    };
   }, [navigate]);
 
   // ---------------------------------------------------------------------------
@@ -187,6 +203,21 @@ export function SetupPage(): React.JSX.Element {
   // Render
   // ---------------------------------------------------------------------------
 
+  if (checking) {
+    return (
+      <div
+        style={{
+          display: "flex",
+          justifyContent: "center",
+          alignItems: "center",
+          minHeight: "100vh",
+        }}
+      >
+        <Spinner size="large" label="Loading…" />
+      </div>
+    );
+  }
+
   return (
     <div className={styles.root}>
       <div className={styles.card}>

frontend/src/pages/__tests__/SetupPage.test.tsx

@@ -0,0 +1,88 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, waitFor } from "@testing-library/react";
+import { MemoryRouter, Routes, Route } from "react-router-dom";
+import { FluentProvider, webLightTheme } from "@fluentui/react-components";
+import { SetupPage } from "../SetupPage";
+
+// Mock the setup API so tests never hit a real network.
+vi.mock("../../api/setup", () => ({
+  getSetupStatus: vi.fn(),
+  submitSetup: vi.fn(),
+}));
+
+// Mock the crypto utility — we only need it to resolve without testing SHA256.
+vi.mock("../../utils/crypto", () => ({
+  sha256Hex: vi.fn().mockResolvedValue("hashed-password"),
+}));
+
+import { getSetupStatus } from "../../api/setup";
+
+const mockedGetSetupStatus = vi.mocked(getSetupStatus);
+
+function renderPage() {
+  return render(
+    <FluentProvider theme={webLightTheme}>
+      <MemoryRouter initialEntries={["/setup"]}>
+        <Routes>
+          <Route path="/setup" element={<SetupPage />} />
+          <Route
+            path="/login"
+            element={<div data-testid="login-page">Login</div>}
+          />
+        </Routes>
+      </MemoryRouter>
+    </FluentProvider>,
+  );
+}
+
+describe("SetupPage", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("shows a full-screen spinner while the setup status check is in flight", () => {
+    // getSetupStatus never resolves — spinner should be visible immediately.
+    mockedGetSetupStatus.mockReturnValue(new Promise(() => {}));
+    renderPage();
+    expect(screen.getByRole("progressbar")).toBeInTheDocument();
+    // Form should NOT be visible yet.
+    expect(
+      screen.queryByRole("heading", { name: /bangui setup/i }),
+    ).not.toBeInTheDocument();
+  });
+
+  it("renders the setup form once the status check resolves (not complete)", async () => {
+    // Task 0.4: form must not flash before the check resolves.
+    mockedGetSetupStatus.mockResolvedValue({ completed: false });
+    renderPage();
+    await waitFor(() => {
+      expect(
+        screen.getByRole("heading", { name: /bangui setup/i }),
+      ).toBeInTheDocument();
+    });
+    // Spinner should be gone.
+    expect(screen.queryByRole("progressbar")).not.toBeInTheDocument();
+  });
+
+  it("redirects to /login when setup is already complete", async () => {
+    mockedGetSetupStatus.mockResolvedValue({ completed: true });
+    renderPage();
+    await waitFor(() => {
+      expect(screen.getByTestId("login-page")).toBeInTheDocument();
+    });
+  });
+
+  it("renders the form and logs a warning when the status check fails", async () => {
+    // Task 0.4: catch block must log a warning and keep the form visible.
+    const warnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
+    mockedGetSetupStatus.mockRejectedValue(new Error("Connection refused"));
+    renderPage();
+    await waitFor(() => {
+      expect(
+        screen.getByRole("heading", { name: /bangui setup/i }),
+      ).toBeInTheDocument();
+    });
+    expect(warnSpy).toHaveBeenCalledOnce();
+    warnSpy.mockRestore();
+  });
+});