feat: VoiceCoach v2 - OpenClaw gateway + Speaches STT/TTS

- pipeline.py: completely rewritten to use Speaches STT/TTS and OpenClaw LLM
- main.py: v2 with OPENCLAW_TOKEN support
- requirements.txt: slimmed (removed anthropic, faster-whisper direct deps)
- Dockerfile: slimmer build (no model pre-download)
- whisper_stt.py, piper_tts.py: removed (replaced by Speaches API)
- docker-compose.yml: v2 with speaches + openclaw services, piper-tts removed
- openclaw-agent/system_prompt.md: new directory with agent system prompt

pipecat-agent/Dockerfile

@@ -1,24 +1,14 @@
 FROM python:3.11-slim
 
-RUN apt-get update && apt-get install -y \
-    libsndfile1 \
-    ffmpeg \
-    && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && apt-get install -y libsndfile1 ffmpeg && \
+    rm -rf /var/lib/apt/lists/*
 
 WORKDIR /app
-
 COPY requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
-
-# Pre-download faster-whisper medium model at build time
-RUN python -c "\
-from faster_whisper import WhisperModel; \
-WhisperModel('medium', device='cpu', compute_type='int8'); \
-print('Whisper model downloaded.')"
-
 COPY . .
 
 HEALTHCHECK --interval=30s --timeout=10s --start-period=30s \
-    CMD python -c "print('pipeline process alive')" || exit 1
+    CMD python -c "import httpx; httpx.get('http://localhost:8080/health').raise_for_status()"
 
 CMD ["python", "main.py"]