feat(container): add pinned Playwright Docker image and compose stack for Matomo bootstrap

- Add Dockerfile based on pinned Playwright image (v1.46.0-jammy) for reproducible browser runtime
- Introduce docker-compose stack (MariaDB + Matomo + one-shot bootstrap)
- Extend Makefile with container image and stack management targets
- Add env.sample for environment-driven bootstrap configuration
- Relax Playwright dependency to >=1.46.0 to keep Nix builds compatible
- Add E2E test ensuring docker-compose bootstrap exits with 0 and prints token

Dockerfile

@@ -0,0 +1,20 @@
+# Playwright Python image with Chromium + all required OS dependencies
+# Version should roughly match your playwright requirement
+FROM mcr.microsoft.com/playwright/python:v1.46.0-jammy
+
+# Keep stdout clean (token-only), logs go to stderr
+ENV PYTHONUNBUFFERED=1
+
+WORKDIR /app
+
+# Install matomo-bootstrap
+# Option A: from PyPI (recommended once published)
+# RUN pip install --no-cache-dir matomo-bootstrap==1.0.1
+
+# Option B: build from source (current repo)
+COPY pyproject.toml README.md LICENSE /app/
+COPY src /app/src
+RUN pip install --no-cache-dir .
+
+# Default entrypoint: environment-driven bootstrap
+ENTRYPOINT ["matomo-bootstrap"]