feat: add Django project scaffold, configuration and container

Environment-variable configuration that fails fast, database-only health
check, JSON request logs with a request id, security headers with a strict
CSP, and a multi-stage non-root Docker image with compose file. Ticket 1.1.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Sk72AxLwQnYttF6VFSxQLt

README.md

@@ -1,3 +1,43 @@
-# ping-mee-self-service-platform
+# Self-Service Portal
 
-The ping-mee self-servicing platform for all users that use the ping-mee network and its resources
+A Django 5.2 LTS container for a user self-service portal. This repository holds the project scaffold: configuration, health check, logging, security headers and the container definition.
+
+## Configuration
+
+All configuration comes from environment variables, validated at startup. If any variable is missing or invalid, the process prints one message that lists every problem (never the values) and exits with a non-zero code. Copy `.env.example` to `.env` and edit it.
+
+| Variable | Required | Default | Meaning |
+| --- | --- | --- | --- |
+| `SECRET_KEY` | yes | | Django secret, at least 32 characters |
+| `ALLOWED_HOSTS` | yes | | Comma-separated host names |
+| `DATA_DIR` | no | `/data` | Existing directory for the SQLite database |
+| `DEBUG` | no | `false` | `true` or `false` |
+| `TRUSTED_PROXIES` | no | empty | Comma-separated IP addresses or networks. Reserved for the client-IP rule in a later entry; currently has no effect |
+| `LOG_LEVEL` | no | `INFO` | `DEBUG`, `INFO`, `WARNING`, `ERROR`, `CRITICAL` |
+| `DEFAULT_TIMEZONE` | no | `Europe/Berlin` | IANA zone used for display; storage is UTC |
+
+## Run in a container
+
+The image is built and run on a Linux host from a checkout of this repository.
+
+```sh
+cp .env.example .env     # then set SECRET_KEY and ALLOWED_HOSTS
+docker compose up --build
+curl -H "Host: <first ALLOWED_HOSTS entry>" http://localhost:8000/healthz   # {"status":"ok"}
+```
+
+The container runs as a non-root user with a read-only root file system. Only the `/data` and `/backups` volumes are writable. It starts one gunicorn worker with threads after applying migrations. Session and CSRF cookies are marked secure, so use the portal through an HTTPS reverse proxy that sets `X-Forwarded-Proto`.
+
+`/healthz` checks the database only. It returns 200 `{"status":"ok"}` or 503 `{"status":"unavailable"}`.
+
+## Develop
+
+Requires Python 3.13 and [uv](https://docs.astral.sh/uv/).
+
+```sh
+uv sync
+uv run pytest
+uv run ruff check .
+```
+
+`pytest` sets its own test environment (see `pyproject.toml`).