fix(update): throttle nightly update badge to once per day

tests/frontend/managers/updateService.test.js

@@ -61,3 +61,106 @@ describe('UpdateService passive checks', () => {
         expect(fetchMock).toHaveBeenCalledWith('/api/lm/check-updates?nightly=false');
     });
 });
+
+describe('UpdateService nightly notification throttling', () => {
+    let fetchMock;
+    let updateToggle;
+    let updateBadge;
+
+    function stubUpdateBadgeDom() {
+        updateToggle = document.createElement('div');
+        updateToggle.className = 'update-toggle';
+        updateBadge = document.createElement('span');
+        updateBadge.className = 'update-badge';
+        updateToggle.appendChild(updateBadge);
+        document.body.appendChild(updateToggle);
+
+        vi.spyOn(document, 'querySelector').mockImplementation((selector) => {
+            if (selector === '.update-toggle') return updateToggle;
+            if (selector === '.update-toggle .update-badge') return updateBadge;
+            return null;
+        });
+    }
+
+    function makeUpdateResponse(channel) {
+        return {
+            success: true,
+            current_version: 'v1.0.0',
+            latest_version: channel === 'nightly' ? 'main-abc1234' : 'v1.1.0',
+            update_available: true,
+            git_info: { short_hash: 'abc123' },
+            has_git: true,
+            nightly: channel === 'nightly',
+            changelog: ['test: change'],
+            releases: [],
+            behind_by: 3,
+            commit_date: '2026-07-31',
+        };
+    }
+
+    beforeEach(() => {
+        fetchMock = vi.fn().mockResolvedValue(createFetchResponse(makeUpdateResponse('release')));
+        global.fetch = fetchMock;
+        stubUpdateBadgeDom();
+    });
+
+    afterEach(() => {
+        vi.restoreAllMocks();
+        delete global.fetch;
+    });
+
+    it('shows the nightly badge once and keeps it visible for the session', async () => {
+        stubSettingsUpdateChannel('nightly');
+        fetchMock.mockResolvedValue(createFetchResponse(makeUpdateResponse('nightly')));
+
+        const service = new UpdateService();
+        service.updateNotificationsEnabled = true;
+
+        await service.checkForUpdates({ force: true });
+
+        expect(service.updateAvailable).toBe(true);
+        expect(service.nightlyBadgeShown).toBe(true);
+        expect(service.nightlyNotifyDate).toBe(service._getTodayKey());
+        expect(updateBadge.classList.contains('visible')).toBe(true);
+
+        // A repeated check within the same session keeps the badge visible.
+        await service.checkForUpdates({ force: true });
+        expect(updateBadge.classList.contains('visible')).toBe(true);
+    });
+
+    it('suppresses the nightly badge on a later session in the same day', async () => {
+        stubSettingsUpdateChannel('nightly');
+        fetchMock.mockResolvedValue(createFetchResponse(makeUpdateResponse('nightly')));
+
+        const firstService = new UpdateService();
+        firstService.updateNotificationsEnabled = true;
+        await firstService.checkForUpdates({ force: true });
+        expect(updateBadge.classList.contains('visible')).toBe(true);
+
+        // Simulate a fresh page session on the same calendar day.
+        const secondService = new UpdateService();
+        secondService.updateNotificationsEnabled = true;
+        await secondService.checkForUpdates({ force: true });
+
+        expect(secondService.updateAvailable).toBe(true);
+        expect(secondService.nightlyBadgeShown).toBe(false);
+        expect(updateBadge.classList.contains('visible')).toBe(false);
+    });
+
+    it('is not affected by the daily limit on the release channel', async () => {
+        stubSettingsUpdateChannel('release');
+        fetchMock.mockResolvedValue(createFetchResponse(makeUpdateResponse('release')));
+
+        const firstService = new UpdateService();
+        firstService.updateNotificationsEnabled = true;
+        await firstService.checkForUpdates({ force: true });
+        expect(updateBadge.classList.contains('visible')).toBe(true);
+
+        const secondService = new UpdateService();
+        secondService.updateNotificationsEnabled = true;
+        await secondService.checkForUpdates({ force: true });
+
+        expect(secondService.updateAvailable).toBe(true);
+        expect(updateBadge.classList.contains('visible')).toBe(true);
+    });
+});