Admin: Word Search theme authoring + tidy word-pool chips

* New "Word Search themes" panel in the Games tab: enter a theme name + words,
  with live validation (4–8 letters, alpha, deduped) and a count vs the 28 needed
  to fill all three sizes. An "✨ Suggest a word" button asks the LLM for one
  fresh word that fits the theme. Save/edit/remove; authored themes join the daily
  fallback rotation alongside the curated ones (wordsearch_themes table). The
  system still handles word distribution across sizes + placement.
* Daily Word pool's added-word chips now scroll within a bounded area so the
  console stays tidy as the list grows.

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

goodnews/db.py

@@ -260,6 +260,13 @@ CREATE TABLE IF NOT EXISTS feedback_replies (
 );
 CREATE INDEX IF NOT EXISTS idx_feedback_replies_fid ON feedback_replies(feedback_id);
 
+CREATE TABLE IF NOT EXISTS wordsearch_themes (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    theme TEXT NOT NULL,
+    words_json TEXT NOT NULL,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
 CREATE TABLE IF NOT EXISTS client_errors (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
     reason TEXT NOT NULL DEFAULT '',