Stage 7 polish: app shell + nav + lobby + settings (Parts A/B/C)

- Screen.svelte shell: nav bar grows, ad+content+tabbar pinned bottom (mobile feel)
- AdBanner.svelte + banner.ts rotator (params, mock long/short, linkify); Header CSS chevron + grow; Menu (bigger CSS hamburger); TabBar + HoldConfirm shared components; user-select:none
- Lobby: hide-empty sections, tab order New/Tournaments/Stats, place-based result badges (result.ts)
- Settings: Board style > Labels (beginner/classic/none) + prefs plumbing (boardlabels.ts); i18n keys + ru mirror

ui/src/screens/Profile.svelte

@@ -1,26 +1,27 @@
 <script lang="ts">
-  import Header from '../components/Header.svelte';
+  import Screen from '../components/Screen.svelte';
   import { app, logout } from '../lib/app.svelte';
   import { t } from '../lib/i18n/index.svelte';
 </script>
 
-<Header title={t('profile.title')} back="/" />
-<main class="page">
-  {#if app.profile}
-    <div class="name">{app.profile.displayName}</div>
-    {#if app.profile.isGuest}<span class="badge">{t('profile.guest')}</span>{/if}
-    <dl>
-      <dt>{t('profile.language')}</dt>
-      <dd>{app.profile.preferredLanguage}</dd>
-      <dt>{t('profile.timezone')}</dt>
-      <dd>{app.profile.timeZone}</dd>
-      <dt>{t('profile.hintBalance')}</dt>
-      <dd>{app.profile.hintBalance}</dd>
-    </dl>
-    <p class="muted">{t('profile.readonly')}</p>
-    <button class="logout" onclick={() => logout()}>{t('login.title')} / logout</button>
-  {/if}
-</main>
+<Screen title={t('profile.title')} back="/">
+  <div class="page">
+    {#if app.profile}
+      <div class="name">{app.profile.displayName}</div>
+      {#if app.profile.isGuest}<span class="badge">{t('profile.guest')}</span>{/if}
+      <dl>
+        <dt>{t('profile.language')}</dt>
+        <dd>{app.profile.preferredLanguage}</dd>
+        <dt>{t('profile.timezone')}</dt>
+        <dd>{app.profile.timeZone}</dd>
+        <dt>{t('profile.hintBalance')}</dt>
+        <dd>{app.profile.hintBalance}</dd>
+      </dl>
+      <p class="muted">{t('profile.readonly')}</p>
+      <button class="logout" onclick={() => logout()}>{t('login.title')} / logout</button>
+    {/if}
+  </div>
+</Screen>
 
 <style>
   .page {