UI: taller tg-fullscreen header + labelled hub tabs

- tg-fullscreen: +20px header height — without the (removed) hamburger the
  title bar lost its bulk and sat flush on Telegram's native nav band.
- Settings/Comms hub tabs gain text labels under the icons (Settings /
  Profile / Friends / Info and Chat / Dictionary); the icon is aria-hidden
  so the label names the button. New i18n keys about.tab, game.dictionary.

ui/src/game/CommsHub.svelte

@@ -38,12 +38,12 @@
 
   {#snippet tabbar()}
     <TabBar>
-      <button class="tab" class:active={tab === 'chat'} onclick={() => (tab = 'chat')} aria-label={t('game.chat')}>
-        <span class="sq">💬</span>
+      <button class="tab" class:active={tab === 'chat'} onclick={() => (tab = 'chat')}>
+        <span class="sq" aria-hidden="true">💬</span><span class="lbl">{t('game.chat')}</span>
       </button>
       {#if active}
-        <button class="tab" class:active={tab === 'dictionary'} onclick={() => (tab = 'dictionary')} aria-label={t('game.checkWord')}>
-          <span class="sq">🔎</span>
+        <button class="tab" class:active={tab === 'dictionary'} onclick={() => (tab = 'dictionary')}>
+          <span class="sq" aria-hidden="true">🔎</span><span class="lbl">{t('game.dictionary')}</span>
         </button>
       {/if}
     </TabBar>