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/screens/NewGame.svelte

@@ -167,6 +167,10 @@
     | { kind: 'seat-change'; index: number }
     | { kind: 'row-delete'; index: number };
   let pad = $state<PadTarget | null>(null);
+  // The row whose delete cross is armed: tapping a row's kebab asks the host PIN, and a correct PIN
+  // arms its ❌ (mirroring the lobby delete) rather than removing it silently. Tapping the kebab again
+  // (or arming another row) clears the authorisation.
+  let deleteRow = $state<number | null>(null);
 
   const padMode = (p: PadTarget): 'set' | 'verify' | 'change' =>
     p.kind === 'host-set' || p.kind === 'seat-set' ? 'set' : p.kind === 'row-delete' ? 'verify' : 'change';
@@ -202,11 +206,32 @@
         else if (r.kind === 'removed') rows[target.index].pin = undefined;
         break;
       case 'row-delete':
-        if (r.kind === 'verified') rows = rows.filter((_, j) => j !== target.index);
+        if (r.kind === 'verified') deleteRow = target.index; // arm the ❌; the actual delete is a tap on it
         break;
     }
   }
 
+  // onKebab toggles a row's delete authorisation: a second tap (already armed) closes it and resets
+  // the host authorisation; otherwise it asks the host PIN (which, on success, arms the ❌).
+  function onKebab(i: number): void {
+    if (deleteRow === i) {
+      deleteRow = null;
+      return;
+    }
+    deleteRow = null; // only one row armed at a time
+    pad = { kind: 'row-delete', index: i };
+  }
+
+  function removeRow(i: number): void {
+    rows = rows.filter((_, j) => j !== i);
+    deleteRow = null;
+  }
+
+  function addRow(): void {
+    rows = [...rows, { name: '', committed: '' }];
+    deleteRow = null;
+  }
+
   function setHostPlays(yes: boolean): void {
     askHostPlays = false;
     if (!yes) return;
@@ -307,60 +332,76 @@
         >{t('new.start')}</button>
       {:else if offlineMode.active}
         <!-- Offline pass-and-play (hotseat): a device-local 2-4 human game. The host sets a master
-             PIN first (it gates the roster); each seat may add its own PIN. -->
+             PIN first (it gates the roster); each seat may add its own PIN. The scrollable region +
+             the pinned Start button mirror the friends form, so a name input's soft keyboard shrinks
+             the region (no full-height spacer that would paint a blank block behind the keyboard). -->
         <div class="fg">
-          <div class="hostpin">
-            <span class="ftitle">{t('hotseat.hostPin')}</span>
-            <button class="plink" onclick={() => (pad = hostPin ? { kind: 'host-change' } : { kind: 'host-set' })}>
-              {hostPin ? t('hotseat.changePin') : t('hotseat.setPin')}
-            </button>
-          </div>
-          <label class="field">
-            <span>{t('new.gameType')}</span>
-            <select bind:value={inviteVariant} class:placeholder={!inviteVariant} disabled={variants.length === 1}>
-              <option value="" disabled>—</option>
-              {#each variants as v (v.id)}<option value={v.id}>{t(v.label)}</option>{/each}
-            </select>
-          </label>
-          {#if inviteVariant && supportsMultipleWordsToggle(inviteVariant)}
-            <label class="toggle">
-              <span>{t('new.multipleWordsPerTurn')}</span>
-              <input type="checkbox" bind:checked={multipleWords} />
-            </label>
-          {/if}
-          <div class="roster">
-            {#each rows as row, i (i)}
-              <div class="prow">
-                <input
-                  class="pname"
-                  class:invalid={row.name.trim() !== '' && !validDisplayName(row.name)}
-                  bind:value={row.name}
-                  disabled={!hostPin}
-                  placeholder={t('hotseat.playerName')}
-                  maxlength="40"
-                  oninput={() => (row.committed = commitName(row.name, row.committed))}
-                  onblur={() => (row.name = row.committed)}
-                />
-                <button class="plink" disabled={!hostPin || row.committed === ''} onclick={() => openSeatPin(i)}>
-                  {row.pin ? t('hotseat.changePin') : t('hotseat.setPin')}
+          <div class="hs-scroll">
+            <div class="hostpin">
+              <span class="ftitle">{t('hotseat.hostPin')}</span>
+              <button class="plink" onclick={() => (pad = hostPin ? { kind: 'host-change' } : { kind: 'host-set' })}>
+                {hostPin ? t('hotseat.changePin') : t('hotseat.setPin')}
+              </button>
+            </div>
+            <!-- Variant plaques + the multiple-words toggle, identical to Quick Match. -->
+            <div class="variants">
+              {#each variants as v (v.id)}
+                <button class="variant" class:selected={inviteVariant === v.id} onclick={() => (inviteVariant = v.id)}>
+                  <span class="vmain">
+                    <span class="vname">{t(v.label)}</span>
+                    {#if VARIANT_FLAG[v.id]}
+                      <span class="vflag">{VARIANT_FLAG[v.id]}</span>
+                    {:else}
+                      <img class="vflag-img" src="flag-ussr.svg" alt="" />
+                    {/if}
+                  </span>
+                  <span class="vrules">{t(VARIANT_RULES[v.id])}</span>
                 </button>
-                {#if rows.length > 2}
-                  <button
-                    class="pkebab"
+              {/each}
+            </div>
+            {#if variants.some((v) => supportsMultipleWordsToggle(v.id))}
+              <label class="toggle">
+                <span>{t('new.multipleWordsPerTurn')}</span>
+                <input type="checkbox" bind:checked={multipleWords} />
+              </label>
+            {/if}
+            <div class="roster">
+              {#each rows as row, i (i)}
+                <div class="prow">
+                  <input
+                    class="pname"
+                    class:invalid={row.name.trim() !== '' && !validDisplayName(row.name)}
+                    bind:value={row.name}
                     disabled={!hostPin}
-                    aria-label={t('hotseat.removePlayer')}
-                    onclick={() => (pad = { kind: 'row-delete', index: i })}
-                  >⋮</button>
-                {/if}
-              </div>
-            {/each}
+                    placeholder={t('hotseat.playerName')}
+                    maxlength="40"
+                    oninput={() => (row.committed = commitName(row.name, row.committed))}
+                    onblur={() => (row.name = row.committed)}
+                  />
+                  <button class="plink" disabled={!hostPin || row.committed === ''} onclick={() => openSeatPin(i)}>
+                    {row.pin ? t('hotseat.changePin') : t('hotseat.setPin')}
+                  </button>
+                  {#if rows.length > 2}
+                    {#if deleteRow === i}
+                      <button class="prow-del" aria-label={t('hotseat.removePlayer')} onclick={() => removeRow(i)}>❌</button>
+                    {/if}
+                    <button
+                      class="pkebab"
+                      class:armed={deleteRow === i}
+                      disabled={!hostPin}
+                      aria-label={t('hotseat.removePlayer')}
+                      onclick={() => onKebab(i)}
+                    >⋮</button>
+                  {/if}
+                </div>
+              {/each}
+            </div>
+            {#if rows.length < 4}
+              <button class="addrow" disabled={!hostPin} onclick={addRow}>
+                + {t('hotseat.addPlayer')}
+              </button>
+            {/if}
           </div>
-          {#if rows.length < 4}
-            <button class="addrow" disabled={!hostPin} onclick={() => (rows = [...rows, { name: '', committed: '' }])}>
-              + {t('hotseat.addPlayer')}
-            </button>
-          {/if}
-          <div class="grow"></div>
           <button
             class="invite"
             disabled={!hostPin || !inviteVariant || !rosterReady(rows) || starting}
@@ -639,6 +680,17 @@
     line-height: 1.4;
   }
   /* --- offline hotseat roster --- */
+  /* The scrollable region (host PIN + variants + roster), pinned above the Start button — mirrors
+     the friends form so a focused name input's soft keyboard shrinks this region (via --vvh on the
+     screen) instead of leaving a full-height blank spacer painted behind the keyboard. */
+  .hs-scroll {
+    flex: 1;
+    min-height: 0;
+    overflow-y: auto;
+    display: flex;
+    flex-direction: column;
+    gap: 14px;
+  }
   .hostpin {
     display: flex;
     align-items: center;
@@ -696,6 +748,18 @@
     font-size: 1.1rem;
     line-height: 1;
   }
+  .pkebab.armed {
+    color: var(--accent);
+  }
+  /* The delete cross a correct host PIN arms next to a player row (mirrors the lobby game delete). */
+  .prow-del {
+    flex: 0 0 auto;
+    padding: 6px 8px;
+    border: none;
+    background: none;
+    font-size: 1rem;
+    line-height: 1;
+  }
   .addrow {
     align-self: flex-start;
     padding: 8px 12px;

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);