trivia: add 8 new categories + per-category dedup cache

New categories: anime, sports, food, history, geography, nature,
mythology, tv (14 total).

Add _trivia_recent dict that tracks the last 20 questions per
category and injects them into the LLM prompt as a avoid list,
preventing duplicate questions within a session.

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

matrixbot/commands.py

@@ -798,12 +798,20 @@ async def cmd_agent(client: AsyncClient, room_id: str, sender: str, args: str):
 
 
 _TRIVIA_CATEGORIES = {
-    "gaming": "video games, gaming history, game mechanics, esports",
-    "tech": "technology, programming, computers, the internet, software",
-    "general": "general knowledge, world facts, history, science, geography",
-    "movies": "movies, film history, actors, directors, pop culture",
-    "music": "music, bands, songs, music history, artists",
-    "science": "science, biology, physics, chemistry, space",
+    "gaming": "video games, gaming history, game mechanics, esports, retro gaming, game franchises",
+    "tech": "technology, programming, computers, the internet, software, hardware, open source, networking",
+    "general": "general knowledge, world facts, history, science, geography, politics, culture",
+    "movies": "movies, film history, actors, directors, pop culture, Oscar winners, franchises",
+    "music": "music, bands, songs, music history, artists, albums, genres",
+    "science": "science, biology, physics, chemistry, space, astronomy, mathematics, medicine",
+    "anime": "anime, manga, Japanese animation, Studio Ghibli, shonen, seinen, classic and modern series",
+    "sports": "sports, athletics, Olympic history, world records, famous athletes, major leagues",
+    "food": "food, cooking, cuisine, world dishes, ingredients, culinary history, chefs",
+    "history": "world history, ancient civilizations, wars, empires, historical figures, timelines",
+    "geography": "world geography, countries, capitals, rivers, mountains, flags, continents",
+    "nature": "nature, animals, wildlife, ecosystems, plants, oceans, weather, environment",
+    "mythology": "mythology, folklore, gods and goddesses, legends, Greek, Norse, Egyptian, world myths",
+    "tv": "television, TV shows, sitcoms, dramas, streaming originals, characters, actors",
 }
 
 _TRIVIA_FALLBACKS = [
@@ -830,11 +838,23 @@ _TRIVIA_FALLBACKS = [
 ]
 
 
+# Per-category cache of recently asked question texts (avoids duplicates)
+_trivia_recent: dict[str, list[str]] = {}
+_TRIVIA_RECENT_MAX = 20
+
+
 async def _generate_trivia_question(category: str) -> dict | None:
     """Ask the LLM to generate a trivia question. Returns None on failure."""
     topic = _TRIVIA_CATEGORIES.get(category, _TRIVIA_CATEGORIES["general"])
+    recent = _trivia_recent.get(category, [])
+    avoid_clause = (
+        " Do NOT ask any of these questions that were recently used: "
+        + "; ".join(f'"{q}"' for q in recent[-10:])
+        + "."
+    ) if recent else ""
     prompt = (
         f"Generate a trivia question about {topic}."
+        + avoid_clause +
         " Respond with ONLY a JSON object, no markdown, no explanation. "
         'Format: {"q": "question text", "options": ["A text", "B text", "C text", "D text"], "answer": 0} '
         "where answer is the 0-based index of the correct option. "
@@ -873,13 +893,18 @@ async def _generate_trivia_question(category: str) -> dict | None:
                     and isinstance(parsed.get("answer"), int)
                     and 0 <= parsed["answer"] <= 3
                 ):
+                    # Record in recent cache to avoid future duplicates
+                    bucket = _trivia_recent.setdefault(category, [])
+                    bucket.append(parsed["q"])
+                    if len(bucket) > _TRIVIA_RECENT_MAX:
+                        bucket.pop(0)
                     return parsed
     except Exception:
         pass
     return None
 
 
-@command("trivia", "Play a trivia game (!trivia [gaming|tech|general|movies|music|science])")
+@command("trivia", "Play a trivia game (!trivia [category] — gaming, tech, science, movies, music, anime, sports, food, history, geography, nature, mythology, tv, general)")
 async def cmd_trivia(client: AsyncClient, room_id: str, sender: str, args: str):
     category = args.strip().lower() if args.strip().lower() in _TRIVIA_CATEGORIES else "general"
     if args.strip() and args.strip().lower() not in _TRIVIA_CATEGORIES: