feat: expand to 1014 words, add title-case display and 2 new themes

- Move word data from hardcoded seed.py to data/words.json
- Expand from 210 words across 7 categories to 1014 words across 14
  categories (animals, food, colors, sports, space, nature, music,
  science, countries, occupations, ocean, weather, mythology, technology)
- Word list sidebar now shows title case (Tiger) while grid stays
  uppercase; text input remains case-insensitive
- Add Ocean theme (light, blue accents) and Forest theme (dark, amber
  accents on deep green)
- Replace hardcoded rgba values with --coral-bg CSS variable so
  selection highlighting adapts per theme

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

handlers/scoreboard.py

@@ -0,0 +1,10 @@
+"""Scoreboard page handler."""
+
+import tornado.web
+
+
+class ScoreboardPageHandler(tornado.web.RequestHandler):
+    """Serves the scoreboard page."""
+
+    def get(self):
+        self.render("scoreboard.html")