fix(offline): hotseat review fixes + PWA stale-shell (SW route order)

Owner review of the pass-and-play PR:
- Roster delete (bug): a correct host PIN now ARMS a delete cross next to
  the row (mirroring the lobby delete) instead of removing it silently;
  tapping the kebab again clears the host authorisation.
- Variant picker (UX): replace the dropdown with the Quick-Match variant
  plaques + the multiple-words toggle, one-to-one.
- Keyboard layout (UX): the roster sits in a scroll region with the Start
  button pinned (friends-form pattern), so a name input's soft keyboard
  shrinks the region instead of leaving a full-height blank spacer painted
  behind the keyboard.
- e2e: variant via plaque + a row-delete (arm then cross) regression step.

PWA stale-version (pre-existing, same PR):
- sw.ts: register the network-first NavigationRoute BEFORE precacheAndRoute.
  Workbox matches in registration order and the precache route (directoryIndex
  index.html) shadowed the shell navigation, serving it cache-first — the old
  build's __APP_VERSION__ until a second load. Fixes both the maintenance
  self-reload and a cold open after a deploy. Doc updated (ARCHITECTURE).

ui/src/sw.ts

@@ -24,17 +24,19 @@ clientsClaim();
 // Drop precaches left by a previous SW revision (including the old install-only shell cache).
 cleanupOutdatedCaches();
 
-// Precache the shell + hashed assets injected at build time — exactly what a cold offline launch
-// needs. The landing page and the old-engine polyfill bundle are excluded via the build globs.
-precacheAndRoute(self.__WB_MANIFEST);
-
 // Navigations are network-first so a new deploy loads immediately when online: fetch the fresh
 // (no-cache) shell from the server — it references the new hashed assets, which are then fetched
 // fresh — and only fall back to the precached shell when the network is unreachable or too slow (a
 // short timeout). This keeps the app up to date online while still cold-launching offline. Only the
-// tiny HTML is re-fetched; the immutable hashed assets stay cache-first (precacheAndRoute above) and
+// tiny HTML is re-fetched; the immutable hashed assets stay cache-first (precacheAndRoute below) and
 // re-download only when their hash — i.e. the version — changes. Deny-list the RPC path and the
 // admin console so those are never resolved to the app shell.
+//
+// This route MUST be registered BEFORE precacheAndRoute: Workbox matches routes in registration
+// order, and the precache route matches shell navigations too (its directoryIndex is index.html), so
+// registering it first would shadow this handler and serve the shell CACHE-FIRST — i.e. the old
+// build's version until the next load. NavigationRoute matches only request.mode === 'navigate', so
+// hashed-asset requests still fall through to the cache-first precache route below.
 const NAV_TIMEOUT_MS = 3000;
 async function freshShell({ request }: { request: Request }): Promise<Response> {
   const ctrl = new AbortController();
@@ -50,3 +52,9 @@ async function freshShell({ request }: { request: Request }): Promise<Response>
   return (await matchPrecache('index.html')) ?? Response.error();
 }
 registerRoute(new NavigationRoute(freshShell, { denylist: [/^\/scrabble\.edge\.v1\.Gateway/, /^\/_gm\//] }));
+
+// Precache the shell + hashed assets injected at build time — exactly what a cold offline launch
+// needs (the precached index.html is also the offline fallback matchPrecache serves above). The
+// immutable hashed assets stay cache-first here; the landing page and the old-engine polyfill bundle
+// are excluded via the build globs.
+precacheAndRoute(self.__WB_MANIFEST);