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>

public/set/manifest.webmanifest

@@ -0,0 +1,14 @@
+{
+  "name": "Two Tales VFX Screen Markers",
+  "short_name": "Markers",
+  "start_url": "/set/",
+  "scope": "/set/",
+  "display": "fullscreen",
+  "orientation": "any",
+  "background_color": "#000000",
+  "theme_color": "#000000",
+  "icons": [
+    { "src": "/icon.png", "sizes": "512x512", "type": "image/png" },
+    { "src": "/apple-icon.png", "sizes": "180x180", "type": "image/png" }
+  ]
+}

public/set/sw.js

@@ -0,0 +1,54 @@
+// Offline cache for /set (screen markers). Crews often have no signal on set:
+// once the page has loaded once, it and every marker image work offline.
+const CACHE = "ttvfx-set-v1";
+
+self.addEventListener("install", (event) => {
+  event.waitUntil(caches.open(CACHE).then((c) => c.addAll(["/set/"])).then(() => self.skipWaiting()));
+});
+
+self.addEventListener("activate", (event) => {
+  event.waitUntil(
+    caches
+      .keys()
+      .then((keys) => Promise.all(keys.filter((k) => k.startsWith("ttvfx-set-") && k !== CACHE).map((k) => caches.delete(k))))
+      .then(() => self.clients.claim()),
+  );
+});
+
+self.addEventListener("fetch", (event) => {
+  const req = event.request;
+  if (req.method !== "GET") return;
+  const url = new URL(req.url);
+  if (url.origin !== self.location.origin) return;
+
+  // Page: network first so updates arrive, cached copy when offline
+  if (req.mode === "navigate") {
+    event.respondWith(
+      fetch(req)
+        .then((res) => {
+          const copy = res.clone();
+          caches.open(CACHE).then((c) => c.put("/set/", copy));
+          return res;
+        })
+        .catch(() => caches.match("/set/")),
+    );
+    return;
+  }
+
+  // Marker images, build assets, fonts, icons: cache first
+  if (url.pathname.startsWith("/set/") || url.pathname.startsWith("/_next/") || /\.(png|woff2|webmanifest)$/.test(url.pathname)) {
+    event.respondWith(
+      caches.match(req).then(
+        (hit) =>
+          hit ||
+          fetch(req).then((res) => {
+            if (res.ok) {
+              const copy = res.clone();
+              caches.open(CACHE).then((c) => c.put(req, copy));
+            }
+            return res;
+          }),
+      ),
+    );
+  }
+});