docs, ci, test: README for gRPC, Dockerfile, CI pipeline, HTTP sink tests

- README: updated for gRPC API, Docker deployment, project structure
- Dockerfile: multi-stage build for containerized deployment
- CI: GitHub Actions workflow for ruff lint + pytest on push/PR
- tests: HTTP sink end-to-end tests (forwarding, 404, delivery)
- tests: comprehensive smoke test exercising all 10 gRPC endpoints

Dockerfile

@@ -0,0 +1,27 @@
+FROM python:3.13-slim AS builder
+
+RUN pip install uv --no-cache-dir
+
+WORKDIR /app
+COPY pyproject.toml .
+RUN uv sync --no-dev --frozen
+
+FROM python:3.13-slim
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    liblmdb0 \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN groupadd -r daena && useradd -r -g daena -d /var/lib/daena daena
+
+COPY --from=builder /app /app
+COPY src/ /app/src/
+COPY proto/ /app/proto/
+
+ENV PATH="/app/.venv/bin:$PATH" \
+    DAENA_CONFIG_PATH=/etc/daena/daena.yaml
+
+EXPOSE 8642
+
+USER daena
+ENTRYPOINT ["daena-serve"]