Initial scaffold: image/ FastAPI app, models.yaml, docs

- image/ FastAPI app: /api/status, /api/swap, /api/swap/{id}/stream, /api/test-connection
- models.yaml: 5-model catalog (qwen3-vl, gemma4, qwen36, qwen3-235b-fp8, qwen25-72b)
- README, runbook, known-issues
- Dry-run swap verified against live Spark 1 (gemma4 currently loaded)

image/Dockerfile

@@ -0,0 +1,21 @@
+FROM python:3.12-slim
+
+RUN apt-get update \
+ && apt-get install -y --no-install-recommends openssh-client curl ca-certificates \
+ && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+COPY pyproject.toml /app/
+COPY app /app/app
+COPY entrypoint.sh /app/entrypoint.sh
+RUN chmod +x /app/entrypoint.sh
+
+# models.yaml is mounted in or copied at build via build-context root.
+# For Docker, build from the repo root: `docker build -f image/Dockerfile .`
+COPY models.yaml /app/models.yaml
+
+RUN pip install --no-cache-dir -e .
+
+ENV BIND_PORT=9999
+EXPOSE 9999
+ENTRYPOINT ["/app/entrypoint.sh"]