Censor profanity: "..." on screen, spoken as "beep"

New profanity.js does whole-word matching against a Russian/English
root list (avoids false positives like "победа", "тебя", "сукно").
Applied once per message before it's used anywhere downstream
(display, TTS, AI reply input) — screen shows "..." in place of a
censored word, while the TTS text uses "бип" so it's heard as a beep
instead of read literally.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Dockerfile

@@ -8,7 +8,7 @@ WORKDIR /app
 COPY package.json package-lock.json* ./
 RUN npm ci --omit=dev
 
-COPY server.js db.js ai-prompt.txt ./
+COPY server.js db.js profanity.js ai-prompt.txt ./
 COPY public ./public
 
 EXPOSE 3000