fix(homepage): add sizes prop to fill images and fix router.events deprecation

Context

After upgrading homepage from Next.js 13.2.3 → 13.5.11 (PR #357), Lighthouse scores regressed:

Metric	Before	After	Delta
Performance	48	43	−5
Best Practices	92	83	−9

Root-cause analysis identified two code-level issues as the primary drivers.

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Fix 1 — Add sizes prop to all fill images

Next.js ≥ 13.4 emits a console.warn whenever a fill image is missing the sizes prop. Lighthouse's no-browser-errors audit treats console warnings as a Best Practices failure, which explains the −9 pt drop from 92 → 83.

Affected files

File	Issue
src/components/banner.jsx:11	sizes="100vh" is a typo — should be 100vw
src/components/imageAndText.jsx:11	fill with no sizes
src/components/logo.jsx	fill with no sizes
src/components/section.jsx:14	fill with no sizes
src/components/column.jsx:10	fill with no sizes
src/components/cards/defaultCard.jsx:22	fill with no sizes

sizes formula (Bootstrap grid)

Use the Bootstrap breakpoints to compute the right value per component:

(max-width: 576px) 100vw, (max-width: 992px) <sm-cols/12*100>vw, <lg-cols/12*100>vw

For example, imageAndText.jsx uses col-sm-5 col-lg-4:

sizes="(max-width: 576px) 100vw, (max-width: 992px) 42vw, 33vw"

---

Fix 2 — Replace router.events with asPath effect

_app.jsx:9-17 uses router.events which is deprecated in the Pages Router since Next.js 13.4, and also has an existing react-hooks/exhaustive-deps lint warning on callback.

Replace with a useEffect keyed on router.asPath:

// Before
const useRouteChangeComplete = (callback) => {
  const router = useRouter();
  useEffect(() => {
    router.events.on('routeChangeComplete', callback);
    return () => router.events.off('routeChangeComplete', callback);
  }, [router.events]);
};

// After (add useRef to imports)
const useRouteChangeComplete = (callback) => {
  const { asPath } = useRouter();
  const isMount = useRef(true);
  useEffect(() => {
    if (isMount.current) { isMount.current = false; return; }
    callback(asPath);
  }, [asPath, callback]);
};

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Acceptance criteria

• No console.warn for missing sizes in browser DevTools on the homepage
• Lighthouse Best Practices score returns to ≥ 92
• Lighthouse Performance score improves toward the 48 baseline
• yarn lint passes with no new warnings