Add /set: on-set screen tracking markers for crews

- Unlinked, noindex page listing marker PNGs from public/set/markers
  (discovered at build time; filenames encode device/resolution/orientation)
- Detects the current screen and offers the closest match first
- One-tap full-screen viewer: wake lock, hidden controls, full grid/edges
  toggle, fill vs fit by aspect, back button closes, deep links via hash
- Offline service worker + home-screen manifest for iPhone full screen
- Marketing chrome moved into an (site) route group so /set has none

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/set/page.tsx

@@ -0,0 +1,27 @@
+import type { Metadata, Viewport } from "next";
+import MarkerPicker from "@/components/set/MarkerPicker";
+import { loadMarkers } from "@/lib/markers";
+
+// On-set screen tracking markers. Deliberately not linked from the site,
+// kept out of search results and the sitemap.
+export const metadata: Metadata = {
+  title: "Screen markers",
+  description: "Two Tales VFX screen tracking markers for production crews.",
+  robots: { index: false, follow: false },
+  manifest: "/set/manifest.webmanifest",
+  appleWebApp: { capable: true, title: "Markers", statusBarStyle: "black-translucent" },
+};
+
+export const viewport: Viewport = {
+  themeColor: "#000000",
+  viewportFit: "cover",
+};
+
+export default function SetPage() {
+  const { screens, extras } = loadMarkers();
+  return (
+    <main className="min-h-dvh bg-ink">
+      <MarkerPicker screens={screens} extras={extras} />
+    </main>
+  );
+}