chore: hide the What's New setting until an entry exists (#1770)

The nav trigger already stays out of the top bar while entries.json is
empty, but the Settings toggle rendered unconditionally, so About showed
a control whose helper text described a sparkle icon that could not
appear. The Preferences section now follows the same rule as the trigger.

Also gives the toggle an accessible name. Its visible text is only
ON/OFF, so a screen reader previously announced the state without the
setting it belongs to.

frontend/src/components/settings/AboutSection.tsx

@@ -2,6 +2,7 @@ import { useLicense } from '@/context/LicenseContext';
 import { TierBadge } from '@/components/TierBadge';
 import { TogglePill } from '@/components/ui/toggle-pill';
 import { useWhatsNewPreference } from '@/hooks/useWhatsNewPreference';
+import { whatsNewEntries } from '@/whats-new/entries';
 import { SettingsSection } from './SettingsSection';
 import { SettingsField } from './SettingsField';
 import {
@@ -44,18 +45,24 @@ export function AboutSection() {
                 ) : null}
             </SettingsSection>
 
-            <SettingsSection title="Preferences">
-                <SettingsField
-                    label="Show What's New"
-                    helper="Highlight the sparkle icon in the top bar when a new feature ships."
-                >
-                    <TogglePill
-                        id="whats-new-enabled"
-                        checked={whatsNewEnabled}
-                        onChange={setWhatsNewEnabled}
-                    />
-                </SettingsField>
-            </SettingsSection>
+            {/* Hidden until an entry exists, matching the nav trigger: the toggle
+                would otherwise control an icon that cannot appear. */}
+            {whatsNewEntries.length > 0 && (
+                <SettingsSection title="Preferences">
+                    <SettingsField
+                        label="Show What's New"
+                        helper="Highlight the sparkle icon in the top bar when a new feature ships."
+                    >
+                        <TogglePill
+                            id="whats-new-enabled"
+                            // Visible text is only ON/OFF, so the setting needs a name.
+                            aria-label="Show What's New"
+                            checked={whatsNewEnabled}
+                            onChange={setWhatsNewEnabled}
+                        />
+                    </SettingsField>
+                </SettingsSection>
+            )}
 
             <SettingsSection title="Links">
                 <SettingsField

frontend/src/components/settings/__tests__/AboutSection.test.tsx

@@ -42,6 +42,11 @@ vi.mock('@/hooks/useWhatsNewPreference', () => ({
     useWhatsNewPreference: () => ({ enabled: true, setEnabled: mockSetEnabled, hasUnseen: false, markSeen: vi.fn() }),
 }));
 
+// The shipped entries.json is empty, so populate it here; the empty state has its own file.
+vi.mock('@/whats-new/entries', () => ({
+    whatsNewEntries: [{ id: 'entry-a', title: 'A feature', blurb: 'Does a thing.' }],
+}));
+
 describe('AboutSection', () => {
     it('renders Plan status and Source, License, and Licensing docs links with exact URLs', () => {
         render(<AboutSection />);
@@ -73,9 +78,16 @@ describe('AboutSection', () => {
 });
 
 describe('AboutSection Preferences', () => {
+    it('shows the Preferences section once an entry exists', () => {
+        render(<AboutSection />);
+        expect(screen.getByText('Preferences')).toBeTruthy();
+        expect(screen.getByText("Show What's New")).toBeTruthy();
+    });
+
     it('toggling "Show What\'s New" calls setEnabled', async () => {
         render(<AboutSection />);
-        await userEvent.click(screen.getByRole('switch'));
+        // Name-scoped so a second toggle landing in About cannot break this.
+        await userEvent.click(screen.getByRole('switch', { name: /Show What's New/i }));
         expect(mockSetEnabled).toHaveBeenCalledWith(false);
     });
 });

frontend/src/components/settings/__tests__/AboutSection.whatsNewEmpty.test.tsx

@@ -0,0 +1,59 @@
+import { describe, it, expect, vi, beforeAll } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import { AboutSection } from '../AboutSection';
+
+beforeAll(() => {
+    // Vite injects this at build time; tests need a stand-in.
+    (globalThis as unknown as { __APP_VERSION__: string }).__APP_VERSION__ = '0.0.0-test';
+});
+
+// Separate file so entries can be mocked empty at module scope, matching the
+// state that ships until the first entry is authored.
+vi.mock('@/whats-new/entries', () => ({ whatsNewEntries: [] }));
+
+vi.mock('@/context/LicenseContext', () => ({
+    useLicense: () => ({
+        license: {
+            tier: 'community',
+            status: 'community',
+            customerName: null,
+            productName: null,
+            maskedKey: null,
+            validUntil: null,
+            trialDaysRemaining: null,
+            instanceId: 'abcdef0123456789',
+            portalUrl: null,
+            isLifetime: false,
+        },
+        isPaid: false,
+        loading: false,
+        licenseStatus: 'ready',
+        licenseReady: true,
+        refresh: vi.fn(),
+        activate: vi.fn(),
+        deactivate: vi.fn(),
+    }),
+}));
+
+vi.mock('@/components/TierBadge', () => ({
+    TierBadge: () => <span>Community</span>,
+}));
+
+vi.mock('@/hooks/useWhatsNewPreference', () => ({
+    useWhatsNewPreference: () => ({ enabled: true, setEnabled: vi.fn(), hasUnseen: false, markSeen: vi.fn() }),
+}));
+
+describe("AboutSection with no What's New entries authored", () => {
+    it('hides the Preferences section entirely, so no toggle describes an absent icon', () => {
+        render(<AboutSection />);
+        expect(screen.queryByText('Preferences')).toBeNull();
+        expect(screen.queryByText("Show What's New")).toBeNull();
+        expect(screen.queryByRole('switch')).toBeNull();
+    });
+
+    it('still renders the rest of the About panel', () => {
+        render(<AboutSection />);
+        expect(screen.getByText('Plan status')).toBeTruthy();
+        expect(screen.getByText('Source code')).toBeTruthy();
+    });
+});