diff --git a/e2e/settings-admin-one-piece.spec.ts b/e2e/settings-admin-one-piece.spec.ts
index 4fc1b69d2..3f10f6540 100644
--- a/e2e/settings-admin-one-piece.spec.ts
+++ b/e2e/settings-admin-one-piece.spec.ts
@@ -58,11 +58,13 @@ const SETTINGS_ROUTES = [
   "/settings/api",
   "/settings/mcp",
   "/settings/advanced",
+  "/settings/preview",
   "/settings/about",
 ] as const;
 
 /**
- * The Layout hub's seven children. They are the routes whose header block
+ * The Arrangement hub's children, plus (v1.44) the module pages under
+ * Modules, which use the same back-link header. They are the routes whose header block
  * changed MOST — the shell used to hand-roll a `space-y-6` between the
  * back-link and the title, and `PageHeader`'s documented contract is
  * `space-y-1.5`. Nothing measured them before, so the step went from 24 px
@@ -73,10 +75,12 @@ const LAYOUT_CHILD_ROUTES = [
   "/settings/layout/dashboard",
   "/settings/layout/insights",
   "/settings/layout/medications",
-  "/settings/layout/mood",
   "/settings/layout/labs",
   "/settings/layout/illness",
   "/settings/layout/vorsorge",
+  "/settings/modules/medications",
+  "/settings/modules/mood",
+  "/settings/modules/labs",
 ] as const;
 
 /** The `space-y-1.5` between a back-link and the title it sits above. */
diff --git a/e2e/settings-mobile-nav.spec.ts b/e2e/settings-mobile-nav.spec.ts
new file mode 100644
index 000000000..e8a115c68
--- /dev/null
+++ b/e2e/settings-mobile-nav.spec.ts
@@ -0,0 +1,47 @@
+import { expect, test } from "./setup/test";
+
+import { STORAGE_STATE_PATH } from "./setup/global-setup";
+
+/**
+ * Settings navigation at 390 px: one button names the current section and
+ * opens a sheet with every section under its group. It replaced a strip of
+ * every section as chips, where most of Settings sat off screen.
+ */
+test.describe("settings navigation on a phone", () => {
+  test.use({ storageState: STORAGE_STATE_PATH });
+
+  test("names the section, opens the grouped list and moves on a tap", async ({
+    page,
+  }) => {
+    await page.setViewportSize({ width: 390, height: 844 });
+    await page.goto("/settings/account", { waitUntil: "domcontentloaded" });
+
+    const trigger = page.locator('[data-slot="settings-mobile-nav-trigger"]');
+    await expect(trigger).toBeVisible({ timeout: 15_000 });
+    await expect(trigger).toContainText("Account");
+
+    // The click can land before hydration; retry until the sheet opens.
+    const list = page.locator('[data-slot="settings-mobile-nav-list"]');
+    await expect(async () => {
+      await trigger.click();
+      await expect(list).toBeVisible({ timeout: 2_000 });
+    }).toPass({ timeout: 15_000 });
+
+    for (const group of ["Account", "Tracking", "Notifications", "System"]) {
+      await expect(
+        list.getByRole("heading", { name: group, exact: true }),
+      ).toBeVisible();
+    }
+
+    await list.getByRole("link", { name: "Security" }).click();
+    await expect(page).toHaveURL(/\/settings\/security$/);
+    await expect(list).toHaveCount(0);
+    await expect(trigger).toContainText("Security");
+
+    // Nothing scrolls sideways.
+    const overflow = await page.evaluate(
+      () => document.documentElement.scrollWidth - window.innerWidth,
+    );
+    expect(overflow).toBeLessThanOrEqual(1);
+  });
+});
diff --git a/e2e/settings-overscroll.spec.ts b/e2e/settings-overscroll.spec.ts
index 59f858dfc..0df30bde2 100644
--- a/e2e/settings-overscroll.spec.ts
+++ b/e2e/settings-overscroll.spec.ts
@@ -33,7 +33,7 @@ const ROUTES = [
   // one-scroll-floor assertion below).
   "/settings/layout/insights",
   "/settings/layout/medications",
-  "/settings/layout/mood",
+  "/settings/modules/mood",
   "/settings/modules",
   "/settings/account",
   "/settings/notifications",
diff --git a/e2e/timezone-profile.spec.ts b/e2e/timezone-profile.spec.ts
index f4865aa1d..7f4177b9a 100644
--- a/e2e/timezone-profile.spec.ts
+++ b/e2e/timezone-profile.spec.ts
@@ -6,7 +6,7 @@ import { STORAGE_STATE_PATH } from "./setup/global-setup";
  * Issue #490 — client-rendered timestamps follow the PROFILE timezone.
  *
  * `/api/auth/me` is mocked with an `Asia/Manila` profile; the sessions
- * card on /settings/privacy renders `lastActiveAt` through
+ * card on /settings/security renders `lastActiveAt` through
  * `useFormatters()`, which reads the localStorage timezone mirror that
  * `fetchMe` fills from the mocked payload. A fixed UTC instant must
  * therefore paint the MANILA wall clock (14:30), never the Berlin
@@ -75,7 +75,7 @@ test.describe("profile-timezone display (#490)", () => {
       }),
     );
 
-    await page.goto("/settings/privacy", { waitUntil: "domcontentloaded" });
+    await page.goto("/settings/security", { waitUntil: "domcontentloaded" });
 
     // The sessions card is collapsed by default — expand it first. The
     // toggle's onClick can be dropped if Playwright clicks before React has
diff --git a/src/components/settings/__tests__/preview-section.test.tsx b/src/components/settings/__tests__/preview-section.test.tsx
new file mode 100644
index 000000000..7dc3e11ba
--- /dev/null
+++ b/src/components/settings/__tests__/preview-section.test.tsx
@@ -0,0 +1,51 @@
+import { describe, expect, it } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+
+import { I18nProvider } from "@/lib/i18n/context";
+import { queryKeys } from "@/lib/query-keys";
+import { PreviewSection } from "../preview-section";
+import { primeLocales } from "@/__tests__/helpers/prime-locales";
+
+primeLocales("de");
+
+function render(topics: boolean | undefined, locale: "en" | "de" = "en") {
+  const client = new QueryClient({
+    defaultOptions: { queries: { retry: false, refetchOnMount: false } },
+  });
+  if (topics !== undefined) {
+    client.setQueryData(queryKeys.previewFeatures(), { topics });
+  }
+  return renderToStaticMarkup(
+    <I18nProvider initialLocale={locale}>
+      <QueryClientProvider client={client}>
+        <PreviewSection />
+      </QueryClientProvider>
+    </I18nProvider>,
+  );
+}
+
+describe("<PreviewSection>", () => {
+  it("shows the Topics switch off by default, saved on change", () => {
+    const html = render(false);
+    expect(html).toContain('data-slot="settings-preview-topics-switch"');
+    expect(html).toMatch(
+      /data-slot="settings-preview-topics-switch"[^>]*aria-checked="false"|aria-checked="false"[^>]*data-slot="settings-preview-topics-switch"/,
+    );
+    expect(html).toContain("Topics (beta)");
+    // A switch, no Save: one save model per card.
+    expect(html).not.toContain('type="submit"');
+  });
+
+  it("reads on once the person switched it on", () => {
+    expect(render(true)).toMatch(
+      /data-slot="settings-preview-topics-switch"[^>]*aria-checked="true"|aria-checked="true"[^>]*data-slot="settings-preview-topics-switch"/,
+    );
+  });
+
+  it("says the existing pages stay as they are and nothing raw leaks", () => {
+    const html = render(false, "de");
+    expect(html).toContain("Themen (Beta)");
+    expect(html).not.toContain("settings.preview.");
+  });
+});