fix(offline): hotseat form — natural scroll + focus-into-view (keyboard)

The nested scroll region regressed the keyboard behaviour (a double
scroll: the whole screen scrolled with a huge blank area under the Start
button, and a focused bottom row hid behind the keyboard). Drop it: the
hotseat form now flows naturally and scrolls with the screen's own scroll
(.page.scrollform: no forced full height, no pinned button), and a name
input scrolls itself into view (centred above the keyboard) on focus.

ui/src/screens/NewGame.svelte

@@ -232,6 +232,14 @@
     deleteRow = null;
   }
 
+  // Centre a focused name input above the soft keyboard: the keyboard shrinks the screen (--vvh),
+  // so wait a beat for it to open + the layout to settle, then scroll the field into view (the
+  // default focus-scroll leaves a bottom row hidden behind the keyboard).
+  function bringIntoView(e: FocusEvent): void {
+    const el = e.currentTarget as HTMLElement;
+    setTimeout(() => el.scrollIntoView({ block: 'center' }), 300);
+  }
+
   function setHostPlays(yes: boolean): void {
     askHostPlays = false;
     if (!yes) return;
@@ -278,7 +286,10 @@
 </script>
 
 <Screen title={t('new.title')} back="/">
-  <div class="page">
+  <!-- The hotseat form flows naturally and scrolls with the screen's own scroll (scrollform: no
+       forced full height, no pinned button) so a focused name input's soft keyboard just scrolls the
+       page rather than fighting a nested scroll region. -->
+  <div class="page" class:scrollform={mode === 'friends' && offlineMode.active}>
       <!-- The auto/friends selector. Online it is hidden for guests (no friends to invite). Offline
            it is always shown: "quick" is the local vs_ai flow, "with friends" is the local
            pass-and-play (hotseat) flow. -->
@@ -332,82 +343,77 @@
         >{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. 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="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>
-              {/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}
-                    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>
-          <button
-            class="invite"
-            disabled={!hostPin || !inviteVariant || !rosterReady(rows) || starting}
-            onclick={startHotseat}
-          >{t('new.start')}</button>
+             PIN first (it gates the roster); each seat may add its own PIN. -->
+        <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>
+          {/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}
+                placeholder={t('hotseat.playerName')}
+                maxlength="40"
+                onfocus={bringIntoView}
+                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}
+        <button
+          class="invite"
+          disabled={!hostPin || !inviteVariant || !rosterReady(rows) || starting}
+          onclick={startHotseat}
+        >{t('new.start')}</button>
       {:else if friends.length === 0}
         <p class="subtitle">{t('new.noFriends')}</p>
       {:else}
@@ -486,6 +492,12 @@
     height: 100%;
     box-sizing: border-box;
   }
+  /* The hotseat form: natural height (grows past the viewport → the screen's own scroll takes over)
+     with no full-height pinning, so a focused name input just scrolls the page above the keyboard. */
+  .page.scrollform {
+    height: auto;
+    min-height: 100%;
+  }
   .subtitle {
     color: var(--text-muted);
     margin: 0;
@@ -680,17 +692,6 @@
     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;