M1: Grundgerüst, Datenmodell und Admin

Django-5.2-Projekt mit uv, django-environ und Docker-Compose-Setup
(web + Postgres, WeasyPrint-Systembibliotheken im Image). Vollständiges
Datenmodell (Firma, Therapeut, Auftraggeber, Teilnehmer, Leistungsart,
Leistung, InvoiceLog, InvoiceCounter) mit Admin, Login-Flow und
Platzhalter-Dashboard. Fortschritt in FORTSCHRITT.md.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016yy3uodsai6Ytt3GJ7tBdz

config/settings.py

@@ -0,0 +1,128 @@
+"""
+Django settings for the Abrechnungssystem project.
+
+Settings are read from environment variables via django-environ so the same
+image runs in dev (docker-compose.override.yml) and prod (docker-compose.yml).
+"""
+
+from pathlib import Path
+
+import environ
+
+BASE_DIR = Path(__file__).resolve().parent.parent
+
+env = environ.Env(
+    DEBUG=(bool, False),
+    ALLOWED_HOSTS=(list, ["*"]),
+)
+
+# Read a local .env if present (Docker passes env directly, so it's optional).
+environ.Env.read_env(BASE_DIR / ".env")
+
+SECRET_KEY = env("SECRET_KEY", default="django-insecure-dev-only-change-me")
+
+DEBUG = env("DEBUG")
+
+ALLOWED_HOSTS = env("ALLOWED_HOSTS")
+
+CSRF_TRUSTED_ORIGINS = env.list("CSRF_TRUSTED_ORIGINS", default=[])
+
+
+# Application definition
+
+INSTALLED_APPS = [
+    "django.contrib.admin",
+    "django.contrib.auth",
+    "django.contrib.contenttypes",
+    "django.contrib.sessions",
+    "django.contrib.messages",
+    "django.contrib.staticfiles",
+    "crispy_forms",
+    "crispy_bootstrap5",
+    "django_tables2",
+    "abrechnung",
+]
+
+MIDDLEWARE = [
+    "django.middleware.security.SecurityMiddleware",
+    "whitenoise.middleware.WhiteNoiseMiddleware",
+    "django.contrib.sessions.middleware.SessionMiddleware",
+    "django.middleware.common.CommonMiddleware",
+    "django.middleware.csrf.CsrfViewMiddleware",
+    "django.contrib.auth.middleware.AuthenticationMiddleware",
+    "django.contrib.messages.middleware.MessageMiddleware",
+    "django.middleware.clickjacking.XFrameOptionsMiddleware",
+]
+
+ROOT_URLCONF = "config.urls"
+
+TEMPLATES = [
+    {
+        "BACKEND": "django.template.backends.django.DjangoTemplates",
+        "DIRS": [BASE_DIR / "templates"],
+        "APP_DIRS": True,
+        "OPTIONS": {
+            "context_processors": [
+                "django.template.context_processors.request",
+                "django.contrib.auth.context_processors.auth",
+                "django.contrib.messages.context_processors.messages",
+            ],
+        },
+    },
+]
+
+WSGI_APPLICATION = "config.wsgi.application"
+
+
+# Database — DATABASE_URL, e.g. postgres://user:pass@db:5432/abrechnung.
+# Falls back to a local SQLite file when DATABASE_URL is unset (e.g. quick tests).
+DATABASES = {
+    "default": env.db(
+        "DATABASE_URL",
+        default=f"sqlite:///{BASE_DIR / 'db.sqlite3'}",
+    )
+}
+
+
+AUTH_PASSWORD_VALIDATORS = [
+    {"NAME": "django.contrib.auth.password_validation.UserAttributeSimilarityValidator"},
+    {"NAME": "django.contrib.auth.password_validation.MinimumLengthValidator"},
+    {"NAME": "django.contrib.auth.password_validation.CommonPasswordValidator"},
+    {"NAME": "django.contrib.auth.password_validation.NumericPasswordValidator"},
+]
+
+
+# Internationalization — German-facing UI.
+LANGUAGE_CODE = "de-de"
+TIME_ZONE = "Europe/Berlin"
+USE_I18N = True
+USE_TZ = True
+
+
+# Static files
+STATIC_URL = "static/"
+STATIC_ROOT = BASE_DIR / "staticfiles"
+STATICFILES_DIRS = [BASE_DIR / "static"]
+STORAGES = {
+    "default": {"BACKEND": "django.core.files.storage.FileSystemStorage"},
+    "staticfiles": {
+        "BACKEND": "whitenoise.storage.CompressedManifestStaticFilesStorage",
+    },
+}
+
+# Media (only used for the seller logo — not for invoice documents).
+MEDIA_URL = "media/"
+MEDIA_ROOT = BASE_DIR / "media"
+
+DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
+
+# Auth flow
+LOGIN_URL = "login"
+LOGIN_REDIRECT_URL = "dashboard"
+LOGOUT_REDIRECT_URL = "login"
+
+# crispy-forms
+CRISPY_ALLOWED_TEMPLATE_PACKS = "bootstrap5"
+CRISPY_TEMPLATE_PACK = "bootstrap5"
+
+DJANGO_TABLES2_TEMPLATE = "django_tables2/bootstrap5.html"