feat(ui): batch of UI polish tweaks

- admin dashboard "Users" count excludes robots (CountUsers, humans only)
- lobby finished-game delete reveal: background matches header/tab-bar (--bg-elev)
- mobile: swipe up on the zoom-out board (no staged tiles) shuffles the rack
- lobby: status icons -25%, game-row top/bottom padding halved
- toast: info tier drifts up ~a tab-bar height while fading over 2s and dismisses
  on tap; error tier unchanged
- game: confirm-move button stays pinned at the right edge; rack tiles shrink to
  fit so a full rack never overflows onto it
- telegram: a successful invite-link redeem shows a welcome window pointing at the bot
- settings: remove the grid-lines toggle; the board is always a gapless checkerboard
- settings/comms hubs: the selected tab highlight wraps icon + label as a pill

Docs: UI_DESIGN (toast, board surface, selected tab), PLAN; e2e updated for the
removed grid-lines toggle.

ui/src/screens/Lobby.svelte

@@ -380,8 +380,8 @@
     align-items: center;
     justify-content: center;
     border: none;
-    background: var(--danger);
-    color: #fff;
+    background: var(--bg-elev);
+    color: var(--text);
     font-size: 1.1rem;
   }
   .row {
@@ -404,7 +404,7 @@
     gap: 12px;
     min-width: 0;
     text-align: left;
-    padding: 10px 6px;
+    padding: 5px 6px;
     border: none;
     background: none;
     color: var(--text);
@@ -471,7 +471,7 @@
     color: var(--text-muted);
   }
   .emoji {
-    font-size: 1.8rem;
+    font-size: 1.35rem;
     line-height: 1;
     flex: 0 0 auto;
   }

ui/src/screens/Settings.svelte

@@ -2,7 +2,6 @@
   import {
     app,
     setBoardLabels,
-    setBoardLines,
     setLocalePref,
     setReduceMotion,
     setTheme,
@@ -62,14 +61,6 @@
         </button>
       {/each}
     </div>
-    <label class="row gridlines">
-      <span>{t('settings.boardLines')}</span>
-      <input
-        type="checkbox"
-        checked={app.boardLines}
-        onchange={(e) => setBoardLines(e.currentTarget.checked)}
-      />
-    </label>
   </section>
 
   <section>
@@ -124,7 +115,4 @@
     align-items: center;
     justify-content: space-between;
   }
-  .gridlines {
-    margin-top: 12px;
-  }
 </style>

ui/src/screens/SettingsHub.svelte

@@ -46,18 +46,18 @@
   {#snippet tabbar()}
     <TabBar>
       <button class="tab" class:active={tab === 'settings'} onclick={() => (tab = 'settings')}>
-        <span class="sq" aria-hidden="true">⚙️</span><span class="lbl">{t('settings.title')}</span>
+        <span class="face"><span class="sq" aria-hidden="true">⚙️</span><span class="lbl">{t('settings.title')}</span></span>
       </button>
       <button class="tab" class:active={tab === 'profile'} onclick={() => (tab = 'profile')}>
-        <span class="sq" aria-hidden="true">👤</span><span class="lbl">{t('profile.title')}</span>
+        <span class="face"><span class="sq" aria-hidden="true">👤</span><span class="lbl">{t('profile.title')}</span></span>
       </button>
       {#if !guest}
         <button class="tab" class:active={tab === 'friends'} onclick={() => (tab = 'friends')}>
-          <span class="sq" aria-hidden="true">🤝{#if app.notifications > 0}<span class="badge">{app.notifications}</span>{/if}</span><span class="lbl">{t('friends.title')}</span>
+          <span class="face"><span class="sq" aria-hidden="true">🤝{#if app.notifications > 0}<span class="badge">{app.notifications}</span>{/if}</span><span class="lbl">{t('friends.title')}</span></span>
         </button>
       {/if}
       <button class="tab" class:active={tab === 'about'} onclick={() => (tab = 'about')}>
-        <span class="sq" aria-hidden="true">ℹ️{#if app.feedbackReplyUnread}<span class="badge">1</span>{/if}</span><span class="lbl">{t('about.tab')}</span>
+        <span class="face"><span class="sq" aria-hidden="true">ℹ️{#if app.feedbackReplyUnread}<span class="badge">1</span>{/if}</span><span class="lbl">{t('about.tab')}</span></span>
       </button>
     </TabBar>
   {/snippet}