feat(agent): Dockerfile for node agent

Python 3.12-slim based image running uvicorn on port 8889. Includes
curl for container health checks.

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

agent/Dockerfile

@@ -0,0 +1,14 @@
+FROM python:3.12-slim
+
+WORKDIR /app
+
+RUN apt-get update && apt-get install -y --no-install-recommends curl && rm -rf /var/lib/apt/lists/*
+
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+COPY . .
+
+EXPOSE 8889
+
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8889"]