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/AttractHero.tsx

@@ -33,7 +33,7 @@ export default function AttractHero() {
 
   return (
     <FileDropZone onFile={handleFile} onError={setError} className="w-full max-w-4xl">
-      <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">
         {/* Backglass glow — stands in for real playfield art; GI-lamp amber + a cyan tube accent. */}
         <div
           aria-hidden
@@ -64,10 +64,10 @@ export default function AttractHero() {
 
           <div className="mt-4 flex flex-col items-center gap-3 sm:flex-row">
             <Button type="button" variant="primary" onClick={() => router.push("/play")}>
-              Insert Coin — Play Demo
+              Play Demo
             </Button>
             <label htmlFor={VPX_FILE_INPUT_ID} className={buttonClassName("outline", "cursor-pointer")}>
-              Load Your Table
+              Load Table
             </label>
           </div>