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>

tests/test_admin.py

@@ -325,15 +325,19 @@ def test_wordsearch_endpoint(tmp_path, monkeypatch):
                         return True
         return False
 
-    themes, sizes = set(), {"small": 8, "med": 11, "large": 14}
+    themes, sizes, per_size = set(), {"small": 8, "med": 11, "large": 14}, {}
     for tier, dim in sizes.items():
         r = tc.get(f"/api/puzzle/wordsearch?variant={tier}").json()
         assert r["game"] == "wordsearch" and r["theme"] and r["size"] == tier
         assert len(r["grid"]) == dim and all(len(row) == dim for row in r["grid"])  # bigger tier → bigger grid
         assert "placements" not in r  # solution cells never sent
         assert all(findable(r["grid"], dim, w) for w in r["words"])  # every word placed → solvable
-        themes.add(r["theme"])
+        themes.add(r["theme"]); per_size[tier] = set(r["words"])
     assert len(themes) == 1  # all sizes share the day's one theme
+    # the three sizes are DISJOINT — each day is three distinct puzzles
+    assert per_size["small"] & per_size["med"] == set()
+    assert per_size["small"] & per_size["large"] == set()
+    assert per_size["med"] & per_size["large"] == set()
     # an unknown size falls back to med
     assert tc.get("/api/puzzle/wordsearch?variant=nope").json()["size"] == "med"
 
@@ -358,6 +362,7 @@ def test_wordsearch_thin_llm_falls_back(tmp_path, monkeypatch):
     assert len(large["words"]) == games.WS_TIERS["large"]["count"]  # still full
 
     # A rich proposal (>= WS_MIN_ACCEPT valid words) is accepted.
-    rich = FakeClient("THEME: Rich Theme\nWORDS: " + ", ".join(chr(65 + i) * 5 for i in range(20)))
+    rich_words = [chr(65 + i) * 5 for i in range(26)] + ["ABCDE", "FGHIJ", "KLMNO", "PQRST"]  # 30 distinct
+    rich = FakeClient("THEME: Rich Theme\nWORDS: " + ", ".join(rich_words))
     p2 = games.generate_wordsearch_puzzle(c, "2026-07-02", client=rich)
     assert p2["theme"] == "Rich Theme" and len(p2["words"]) >= games.WS_MIN_ACCEPT