Games batch: neutral words/themes, Word Search sizes + per-word colours

From playtesting findings:
* Pools nearly doubled (115/104 → 228/201) with calm/neutral everyday words
  (claps, dance, drench, beach…), not just strictly-upbeat ones — more variety,
  ~7-month runway. The post-solve "why" prompt reworded to fit neutral words.
* Word Search now stores one theme + word list per day; the grid is built per
  request for three SIZE tiers — Small (8×8, 6 words), Medium (11×11, 9),
  Large (14×14, 13). Large packs more words = a longer sit ("too fast" fix).
  All sizes share the day's theme; every size still code-placed + solvable.
* Word Search themes can now be neutral everyday scenes ("Around the house",
  "At the beach", "In the kitchen", "A walk outdoors", "Making music"…), not
  only hopeful — same shape as the articles.
* Each found word gets its own colour from a calm palette, in the grid and its
  word-list chip. Per-size local progress + best time.

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

goodnews/api.py

@@ -1435,7 +1435,7 @@ def create_app() -> FastAPI:
             if game == "word" and variant in games.WORD_VARIANTS:
                 return games.word_puzzle_response(conn, local_today(), variant)
             if game == "wordsearch":
-                return games.wordsearch_response(conn, local_today())
+                return games.wordsearch_response(conn, local_today(), variant)
         raise HTTPException(status_code=404, detail="no such puzzle")
 
     @app.post("/api/puzzle/word/guess")