feat(ui): vs-AI comms trim, overlay confirm button, recall-to-slot drag

- vs-AI: the comms hub drops the Chat tab (Dictionary only); a finished AI
  game has no comms at all, so its 💬 history-header entry is hidden too.
- Confirm-move ✅: redone as an absolute overlay pinned to the right edge (its
  right edge sits under the preview caption), so the rack keeps a fixed tile
  size — this reverts the tile-shrink that resized the letters at 6 tiles.
- Recall: dragging a placed tile back to the rack now drops it at the slot the
  pointer is over (drag-to-position, a gap opens), instead of snapping to its
  original slot; double-tap still recalls to the origin. New pure recallToSlot.

Tests: placement recallToSlot units; e2e recall-to-position; vs-AI comms e2e
updated. Docs: UI_DESIGN + FUNCTIONAL (+ru).

ui/src/game/CommsHub.svelte

@@ -8,19 +8,24 @@
 
   // The in-game comms hub: a single nav bar + bottom tab bar hosting Chat and the word
   // Dictionary. Tabs switch in place, so the back control always returns to the game. The
-  // Dictionary tab is offered only while the game is active (mirrors the old "check word").
+  // Dictionary tab is offered only while the game is active (mirrors the old "check word"); an
+  // honest-AI game has no Chat, so it shows the Dictionary alone.
   type CommsTab = 'chat' | 'dictionary';
   let { id, initialTab = 'chat' }: { id: string; initialTab?: CommsTab } = $props();
 
   // The game is rendered (and cached) before its comms open, so the cache tells us whether
   // it is still active without another fetch; an unknown game keeps the Dictionary offered.
   const active = $derived(getCachedGame(id)?.view.game.status !== 'finished');
-  // Seeded once from the entry route's tab and then owned locally; the effect below
-  // corrects a Dictionary deep-link into a finished game back to Chat.
+  // An honest-AI game has no chat at all, so its hub is Dictionary-only.
+  const vsAi = $derived(getCachedGame(id)?.view.game.vsAi ?? false);
+  // Seeded once from the entry route's tab, then owned locally. The effect keeps the tab valid:
+  // an AI game has only the Dictionary; a finished non-AI game has only Chat (a stale Dictionary
+  // deep-link falls back to Chat).
   // svelte-ignore state_referenced_locally
   let tab = $state<CommsTab>(initialTab);
   $effect(() => {
-    if (tab === 'dictionary' && !active) tab = 'chat';
+    if (vsAi) tab = 'dictionary';
+    else if (tab === 'dictionary' && !active) tab = 'chat';
   });
 </script>
 
@@ -38,9 +43,11 @@
 
   {#snippet tabbar()}
     <TabBar>
-      <button class="tab" class:active={tab === 'chat'} onclick={() => (tab = 'chat')}>
-        <span class="face"><span class="sq" aria-hidden="true">💬</span><span class="lbl">{t('game.chat')}</span></span>
-      </button>
+      {#if !vsAi}
+        <button class="tab" class:active={tab === 'chat'} onclick={() => (tab = 'chat')}>
+          <span class="face"><span class="sq" aria-hidden="true">💬</span><span class="lbl">{t('game.chat')}</span></span>
+        </button>
+      {/if}
       {#if active}
         <button class="tab" class:active={tab === 'dictionary'} onclick={() => (tab = 'dictionary')}>
           <span class="face"><span class="sq" aria-hidden="true">🔎</span><span class="lbl">{t('game.dictionary')}</span></span>