feat(04-03): add matrix bot containerization

- add Dockerfile for matrix bot runtime
- add compose service and env template entries

Dockerfile

@@ -0,0 +1,27 @@
+FROM python:3.11-slim
+
+WORKDIR /app
+
+ENV PYTHONUNBUFFERED=1
+ENV PYTHONPATH=/app
+ENV UV_PROJECT_ENVIRONMENT=/usr/local
+
+# Install uv for dependency management inside the container.
+RUN pip install --no-cache-dir uv
+
+# Copy dependency manifests first for layer caching.
+COPY pyproject.toml uv.lock* ./
+
+# Install project dependencies into the system environment.
+RUN uv sync --no-dev --no-install-project --frozen 2>/dev/null || uv sync --no-dev --no-install-project
+
+# Copy project source after dependency layers.
+COPY . .
+
+# Install the project itself and keep runtime dependencies in sync.
+RUN uv sync --no-dev --frozen 2>/dev/null || uv sync --no-dev
+
+# Install lambda_agent_api from the local source tree, bypassing its Python version guard.
+RUN pip install --no-cache-dir --ignore-requires-python /app/external/platform-agent_api
+
+CMD ["python", "-m", "adapter.matrix.bot"]