Polish home CTAs, panel rounding, and 404 label; fix dev-mode SW crash

- Shorten CTA labels to "Play Demo" / "Load Table"
- Fix mismatched corner radii on the hero and table-staging panels
- Add horizontal padding to the in-game "insert coin" hint on mobile
- Match the 404 page's "TILT" eyebrow label size to the rest of the site
- Only register the service worker in production — it precaches
  /404.html, which doesn't exist as a static file under `next dev` and
  was failing cache.addAll() on every load

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

components/RegisterServiceWorker.tsx

@@ -4,6 +4,10 @@ import { useEffect } from "react";
 
 export default function RegisterServiceWorker() {
   useEffect(() => {
+    // sw.js precaches /404.html, which only exists as a static file after
+    // `next build`'s static export — under `next dev` it 404s and fails the
+    // whole cache.addAll(), so only register outside of development.
+    if (process.env.NODE_ENV !== "production") return;
     if (!("serviceWorker" in navigator)) return;
     navigator.serviceWorker.register("/sw.js").catch((err) => {
       console.error("Service worker registration failed:", err);