feat(noitu): add the noitu HTML5 Telegram game

Serve the BotFather game noitu from the bot's HTTP server under
/games/noitu when GAME_BASE_URL is set. /noitu sends the game, Play
answers with a signed, expiring link, and the server validates every
word against the embedded noitu dictionary (CC BY-SA 4.0), runs the
bot opponent and turn timer, and reports the score with setGameScore.

Modules can now register game-short-name callbacks and HTTP routes.

.env.example

@@ -15,7 +15,7 @@ MONGO_DATABASE=tiennm99bot
 # Comma-separated module list. Empty = load every module, including any module
 # added later — so list them explicitly when a deployment should only gain a new
 # module deliberately.
-MODULES=util,misc,random,amlich,wordle,loldle,lol,stock,gold,coin,stats,monkeyd,sticker,alias,blacklist,weather
+MODULES=util,misc,random,amlich,wordle,loldle,noitu,lol,stock,gold,coin,stats,monkeyd,sticker,alias,blacklist,weather
 # Telegram user id for owner-only commands.
 OWNER_ID=
 # Comma-separated admin Telegram user ids.
@@ -49,10 +49,24 @@ LOL_PANDASCORE_TOKEN=
 # only when running the bot outside compose. Leave blank to fall back to text.
 RENDERER_URL=
 
+# Optional public HTTPS base URL for the noitu HTML5 game, e.g.
+# https://noitu.example.com. It must route to the bot container's port 8080
+# (attach a Coolify domain to the bot service); the game page is served under
+# <GAME_BASE_URL>/games/noitu/. Unset or invalid = the game is disabled: /noitu
+# still sends the game, Play explains it is not configured, and no /games/
+# route exists. See docs/noitu-game.md.
+GAME_BASE_URL=
+
+# Optional secret (at least 32 bytes) that signs noitu game links. Unset = a key
+# derived from TELEGRAM_BOT_TOKEN, so rotating the bot token invalidates open
+# game links. A value shorter than 32 bytes disables the game. Secret.
+NOITU_GAME_SECRET=
+
 # ====================== Leave UNSET on self-host ==================
 # Defaults are correct for self-host:
 #   KV_PROVIDER          — auto-selects mongodb because MONGO_URL is set
-#   PORT                 — defaults to 8080 (internal health server)
+#   PORT                 — defaults to 8080 (health server, plus the noitu game
+#                          when GAME_BASE_URL is set)
 #   TELEGRAM_WEBHOOK_SECRET — long polling has no webhook
 #   GOLD_VNAPP_API_KEY   — gold module auto-fetches + caches the key to Mongo
 # Stock/coin/gold URL env overrides are not supported; modules use coded