fix(charts): drop the redundant resize sync from useViewportWidth

The useState lazy initialiser already runs on the client during
hydration and reads the live `window.innerWidth`, so the post-mount
handler() call was a no-op that triggered a setState inside useEffect.
The eslint react-hooks/set-state-in-effect rule flags this pattern;
removing it lets the resize + orientationchange listeners alone drive
updates without a hydration-time double set.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/hooks/use-viewport-width.ts

@@ -22,9 +22,6 @@ export function useViewportWidth(): number {
     const handler = () => setWidth(getViewportWidth());
     window.addEventListener("resize", handler);
     window.addEventListener("orientationchange", handler);
-    // Sync once after mount in case the SSR default differs from the
-    // first browser-side measurement.
-    handler();
     return () => {
       window.removeEventListener("resize", handler);
       window.removeEventListener("orientationchange", handler);