fix(epg): keep N from scrolling back to an off-screen focused programme

The guide revealed the keyboard focus after every handled key, so N's
smooth jump to now was cancelled by a reveal scroll whenever a programme
cell was still focused outside the visible lane. Only keys that move the
focus reveal it now.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libs/ui/epg/src/lib/epg-guide/epg-guide.component.spec.ts

@@ -447,6 +447,28 @@ describe('EpgGuideComponent', () => {
         ]);
     });
 
+    it('jumps to now on N without scrolling back to a focus left off-screen', async () => {
+        await settle(fixture);
+        const viewportEl: HTMLElement = fixture.debugElement.query(
+            By.css('cdk-virtual-scroll-viewport')
+        ).nativeElement;
+        const scrollTo = jest.fn();
+        viewportEl.scrollTo = scrollTo as unknown as HTMLElement['scrollTo'];
+        // jsdom reports a zero-sized lane, so this programme counts as hidden.
+        component.focusCell(0, 0);
+        await settle(fixture);
+        scrollTo.mockClear();
+
+        component.onKeydown(keydown('n'));
+
+        // One combined smooth scroll; a reveal after it would cancel it.
+        expect(scrollTo).toHaveBeenCalledTimes(1);
+        expect(scrollTo).toHaveBeenCalledWith(
+            expect.objectContaining({ top: 0, behavior: 'smooth' })
+        );
+        expect(component.focus()).toEqual({ row: 0, block: 0 });
+    });
+
     it('moves the roving focus to a clicked programme card', async () => {
         await settle(fixture);
         const card = fixture.debugElement.query(

libs/ui/epg/src/lib/epg-guide/epg-guide.component.ts

@@ -257,11 +257,16 @@ export class EpgGuideComponent implements OnDestroy {
      */
     @HostListener('document:keydown', ['$event'])
     onKeydown(event: KeyboardEvent): void {
+        const focusBefore = this.focus();
         if (!this.keyboard.handle(event)) {
             return;
         }
         event.preventDefault();
-        this.viewportController.revealFocus(this.focus());
+        // Only a key that moved the focus scrolls to it: N scrolls to now on
+        // its own, and a reveal of a focus left off-screen would cancel it.
+        if (this.focus() !== focusBefore) {
+            this.viewportController.revealFocus(this.focus());
+        }
         afterNextRender(() => this.viewportController.focusRovingTarget(), {
             injector: this.injector,
         });