Word Search mobile: focused viewport, theme placement, unique-per-size words

Per field feedback.
* Each day is now THREE distinct puzzles: the three sizes draw DISJOINT word
  slices from a date-shuffled pool (small/med/large = 6/9/13, sum 28 unique).
  Curated fallback themes expanded to 30 words each; LLM proposals accepted only
  if they supply >= 28 unique words, else fall back. No more repeats across sizes.
* Word Search is now a focused game screen on mobile (same as Daily Word): body
  scroll locked + footer hidden (generalized .playing-game), and the grid sizes
  to the largest square that fits between the theme and the palette (container
  query) — the whole puzzle is on screen, no page scroll.
* Theme placement: full "Today's theme · <name>" on the size-selection screen;
  just the theme name on the puzzle itself, saving vertical space for Large.
* cosy → cozy. 🇺🇸

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/routes/play/+page.svelte

@@ -101,24 +101,27 @@
     }
   });
 
-  // Daily Word on mobile = a focused viewport: lock scroll + hide footer. Cleanup
+  // Any puzzle on mobile = a focused viewport: lock scroll + hide footer. Cleanup
   // ALWAYS removes the class (re-run or unmount), so leaving /play can't strand it.
   $effect(() => {
     if (typeof document === 'undefined') return;
-    if (view === 'play' && game === 'word') {
-      document.documentElement.classList.add('playing-word');
-      return () => document.documentElement.classList.remove('playing-word');
+    if (view === 'play') {
+      document.documentElement.classList.add('playing-game');
+      return () => document.documentElement.classList.remove('playing-game');
     }
   });
 
   const WS_OPTS = [
-    ['small', 'Small', 'cosy · 8×8'],
+    ['small', 'Small', 'cozy · 8×8'],
     ['med', 'Medium', 'balanced · 11×11'],
     ['large', 'Large', 'a longer sit · 14×14'],
   ];
 
+  let wsTheme = $state('');
+
   onMount(async () => {
     try { date = (await getJSON('/api/puzzle/word?variant=5')).date; } catch { /* offline */ }
+    try { wsTheme = (await getJSON('/api/puzzle/wordsearch?variant=med')).theme; } catch { /* offline */ }
     refreshStatus();
   });
   // Refresh hub/selection statuses whenever we land on a screen (incl. Back).
@@ -140,7 +143,7 @@
   </div>
 </header>
 
-<main class="container page" class:gameview={view === 'play' && game === 'word'}>
+<main class="container page" class:gameview={view === 'play'}>
   {#if view === 'hub'}
     <h1>Play</h1>
     <p class="sub">A small calm thing after the brief. One of each a day — no rush, no score to beat but your own.</p>
@@ -165,6 +168,9 @@
 
   {:else if view === 'select'}
     <h1 class="seltitle">{game === 'word' ? 'Daily Word' : 'Word Search'}</h1>
+    {#if game === 'wordsearch' && wsTheme}
+      <p class="wstheme"><span>Today’s theme</span>{wsTheme}</p>
+    {/if}
     <p class="sub">{game === 'word' ? 'Pick your length.' : 'Pick your size.'}</p>
     <div class="opts">
       {#if game === 'word'}
@@ -206,6 +212,9 @@
   h1 { font-size: clamp(2rem, 5vw, 2.6rem); margin: 6px 0 6px; }
   .seltitle { font-size: clamp(1.7rem, 4.5vw, 2.2rem); }
   .sub { color: var(--muted); margin: 0 0 24px; max-width: 540px; }
+  .wstheme { font-family: var(--serif); font-size: 1.6rem; color: var(--accent-deep); margin: 4px 0 18px; }
+  .wstheme span { display: block; text-transform: uppercase; letter-spacing: 0.1em; font-size: 0.66rem;
+                  font-family: var(--label); color: var(--muted); margin-bottom: 3px; }
 
   .cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
   .gamecard {