gx10/tts: persist Piper /tts source + manifest (telephony TTS port baseline)

Dockerfile (linux/arm64, en_US-amy-medium baked), tts_service.py (16kHz/16-bit/mono
WAV, numpy resample 22050->16000), gx10-tts.yaml (CPU NodePort 30850, no GPU request),
README (build/import/cutover/verify on the GX10 cluster).

gx10/tts/Dockerfile

@@ -0,0 +1,31 @@
+# GX10 Piper TTS — linux/arm64 (built natively on the GX10 / DGX Spark, aarch64).
+# Serves the telephony /tts contract: POST {"text"} -> 16 kHz/16-bit/mono WAV.
+# Voice baked into the image so there is no runtime HuggingFace dependency.
+FROM python:3.12-slim
+
+# espeak-ng is the phonemizer backend piper-tts uses at synthesis time.
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends espeak-ng ca-certificates curl \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN pip install --no-cache-dir piper-tts flask numpy
+
+# Bake the voice model (en_US-amy-medium, 22.05 kHz native) into the image.
+ARG PIPER_VOICE=en_US-amy-medium
+ARG VOICE_BASE=https://huggingface.co/rhasspy/piper-voices/resolve/v1.0.0/en/en_US/amy/medium
+RUN mkdir -p /voices \
+    && curl -sSL -o "/voices/${PIPER_VOICE}.onnx" "${VOICE_BASE}/${PIPER_VOICE}.onnx" \
+    && curl -sSL -o "/voices/${PIPER_VOICE}.onnx.json" "${VOICE_BASE}/${PIPER_VOICE}.onnx.json" \
+    && test -s "/voices/${PIPER_VOICE}.onnx" \
+    && test -s "/voices/${PIPER_VOICE}.onnx.json"
+
+COPY tts_service.py /app/tts_service.py
+WORKDIR /app
+
+ENV TTS_PORT=8500 \
+    PIPER_VOICE=en_US-amy-medium \
+    VOICES_DIR=/voices \
+    TARGET_RATE=16000
+
+EXPOSE 8500
+CMD ["python", "tts_service.py"]