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/landing/TableStaging.tsx

@@ -30,7 +30,7 @@ export default function TableStaging({ vpxFile, onPlay, onCancel }: TableStaging
   };
 
   return (
-    <div className="relative overflow-hidden rounded-t-3xl rounded-b-lg border-2 border-chrome/40 bg-ash shadow-2xl">
+    <div className="relative overflow-hidden rounded-lg border-2 border-chrome/40 bg-ash shadow-2xl">
       <div className="relative flex flex-col items-center gap-5 px-4 py-14 text-center sm:px-8">
         <p className="font-mono text-xs tracking-[0.3em] text-arc">TABLE SELECTED</p>
         <h2 className="max-w-lg truncate font-display text-3xl font-black tracking-wide text-paper sm:text-4xl">