docs: Piper-Test auf AR, PT und ZH erweitern

Verifikationsabschnitt: Piper-Test deckt jetzt alle 10 Sprachen ab.
AR/PT/ZH haben kein Geschlechtspaar — liefern dieselbe Stimme für ♂+♀
(kareem, faber, huayan). Kommentare im Test machen das explizit.

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

DEPLOYMENT.md

@@ -1042,7 +1042,7 @@ curl -s --no-buffer \
   "http://127.0.0.1:8003/ws/voice?session_id=test" | head -1
 # Erwartet: HTTP/1.1 101 Switching Protocols
 
-# Piper — alle Geschlechtspaare testen (DE/EN/FR/ES/IT/RU/PL je ♂+♀)
+# Piper — alle Stimmen testen (DE/EN/FR/ES/IT/RU/PL je ♂+♀; AR/ZH/PT nur eine Stimme)
 cd /opt/voice-assistant && sudo -u voice .venv/bin/python - << 'EOF'
 import asyncio
 from app.providers.tts.piper import PiperTTSProvider
@@ -1058,6 +1058,9 @@ async def run():
         ("it","f","Ciao!"),      ("it","m","Ciao!"),
         ("ru","f","Привет!"),    ("ru","m","Привет!"),
         ("pl","f","Cześć!"),     ("pl","m","Cześć!"),
+        ("ar","f","مرحباً!"),    ("ar","m","مرحباً!"),   # → immer kareem (kein ♀)
+        ("pt","f","Bom dia!"),   ("pt","m","Bom dia!"),  # → immer faber (kein ♀)
+        ("zh","f","你好！"),      ("zh","m","你好！"),    # → immer huayan (kein ♂)
     ]:
         voice = voice_for_route("piper", lang, gender)
         audio = await p.synthesize(text, voice=voice, audio_format="pcm")