[django] configure settings via django-environ

django-environ reads from a file `.env` which is not under version
control.

Perhaps we should add a `.env.dist` or similar.

config/settings.py

@@ -10,20 +10,23 @@ For the full list of settings and their values, see
 https://docs.djangoproject.com/en/5.1/ref/settings/
 """
 
+import environ
+import os
 from pathlib import Path
 
-# Build paths inside the project like this: BASE_DIR / 'subdir'.
 BASE_DIR = Path(__file__).resolve().parent.parent
+env = environ.Env(DEBUG=(bool, False))
+environ.Env.read_env(BASE_DIR / ".env")
 
 
 # Quick-start development settings - unsuitable for production
 # See https://docs.djangoproject.com/en/5.1/howto/deployment/checklist/
 
 # SECURITY WARNING: keep the secret key used in production secret!
-SECRET_KEY = "django-insecure-x=%#_wxu0h=d*m#seui9+mjh3vu7of8+4+gpwj@556$un0r1%$"
+SECRET_KEY = env("SECRET_KEY")
 
 # SECURITY WARNING: don't run with debug turned on in production!
-DEBUG = True
+DEBUG = env("DEBUG")
 
 ALLOWED_HOSTS = []
 
@@ -74,10 +77,7 @@ WSGI_APPLICATION = "config.wsgi.application"
 # https://docs.djangoproject.com/en/5.1/ref/settings/#databases
 
 DATABASES = {
-    "default": {
-        "ENGINE": "django.db.backends.sqlite3",
-        "NAME": BASE_DIR / "db.sqlite3",
-    }
+    "default": env.db(),
 }