feat: add streaming TTS service with Coqui XTTS

- tts_streaming.py: NATS-based TTS using XTTS HTTP API
- Streaming audio chunks for low-latency playback
- Voice cloning support via reference audio
- Multi-language synthesis
- OpenTelemetry instrumentation with HyperDX support

Dockerfile

@@ -0,0 +1,14 @@
+FROM python:3.12-slim
+
+WORKDIR /app
+
+# Copy requirements and install dependencies
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy application code
+COPY tts_streaming.py .
+COPY healthcheck.py .
+
+# Run the service
+CMD ["python", "tts_streaming.py"]