fix(layout): fit names on phones without sideways scroll

Display and game names shrink to 0.875rem, then end with an ellipsis
(FitText + fit-text utility, CSS container units, full text in title).
Rows and buttons wrap at large fonts, header points chip can shrink.
Guard: scripts/check-overflow.js.

src/components/AppHeader.points.test.jsx

@@ -31,7 +31,7 @@ describe('AppHeader points chip', () => {
 
         fireEvent.click(screen.getByText('load'));
 
-        const chip = await screen.findByTitle('POINTS.TITLE');
+        const chip = await screen.findByTitle('POINTS.TITLE: 135');
         expect(chip.textContent).toBe('135');
         expect(chip.getAttribute('href')).toBe('/points');
     });