feat(web): remove scan-schedule admin UI (scheduler retired)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/routes/admin/admin.test.ts

@@ -42,21 +42,7 @@ vi.mock('$lib/api/admin', async () => {
     deleteQuarantineViaLidarr: vi.fn().mockResolvedValue({}),
     triggerScan: vi.fn().mockResolvedValue({}),
     refetchMissingCovers: vi.fn().mockResolvedValue({ started: true }),
-    researchMissingArt: vi.fn().mockResolvedValue({ version: 1 }),
-    createScanScheduleQuery: vi.fn(() =>
-      readable({
-        data: {
-          mode: 'off',
-          interval_hours: null,
-          time_of_day: null,
-          weekly_day: null,
-          next_scheduled_at: null,
-        },
-        isPending: false,
-        isError: false
-      })
-    ),
-    updateScanSchedule: vi.fn().mockResolvedValue({})
+    researchMissingArt: vi.fn().mockResolvedValue({ version: 1 })
   };
 });
 
@@ -250,14 +236,6 @@ describe('admin Overview page', () => {
     );
   });
 
-  test('renders the scan-schedule section with mode=off default', () => {
-    setupOverview();
-    render(OverviewPage);
-    expect(screen.getByText('Scan schedule')).toBeInTheDocument();
-    const select = screen.getByLabelText('Mode') as HTMLSelectElement;
-    expect(select.value).toBe('off');
-  });
-
   test('renders Re-search missing art button and invokes on click', async () => {
     setupOverview();
     render(OverviewPage);