UPDATE

config/settings.py

@@ -1,7 +1,12 @@
 import os
+import importlib.util
 from pathlib import Path
 
-from dotenv import load_dotenv
+try:
+    from dotenv import load_dotenv
+except ImportError:  # pragma: no cover - optional in stripped test envs
+    def load_dotenv():
+        return False
 
 load_dotenv()
 
@@ -20,10 +25,6 @@ INSTALLED_APPS = [
     "django.contrib.sessions",
     "django.contrib.messages",
     "django.contrib.staticfiles",
-    "rest_framework",
-    "corsheaders",
-    "drf_spectacular",
-    "drf_spectacular_sidecar",
     "dashboard_data",
     "rag",
     "location_data",
@@ -32,11 +33,20 @@ INSTALLED_APPS = [
     "plant",
     "irrigation",
     "fertilization",
+    "crop_simulation.apps.CropSimulationConfig",
 ]
 
+for optional_app in [
+    "rest_framework",
+    "corsheaders",
+    "drf_spectacular",
+    "drf_spectacular_sidecar",
+]:
+    if importlib.util.find_spec(optional_app):
+        INSTALLED_APPS.insert(6, optional_app)
+
 MIDDLEWARE = [
     "django.middleware.security.SecurityMiddleware",
-    "corsheaders.middleware.CorsMiddleware",
     "django.contrib.sessions.middleware.SessionMiddleware",
     "django.middleware.common.CommonMiddleware",
     "django.middleware.csrf.CsrfViewMiddleware",
@@ -45,6 +55,9 @@ MIDDLEWARE = [
     "django.middleware.clickjacking.XFrameOptionsMiddleware",
 ]
 
+if importlib.util.find_spec("corsheaders"):
+    MIDDLEWARE.insert(1, "corsheaders.middleware.CorsMiddleware")
+
 ROOT_URLCONF = "config.urls"
 WSGI_APPLICATION = "config.wsgi.application"
 
@@ -72,12 +85,12 @@ DATABASES = {
         "PASSWORD": os.environ.get("DB_PASSWORD", ""),
         "HOST": os.environ.get("DB_HOST", "127.0.0.1"),
         "PORT": os.environ.get("DB_PORT", "3306"),
-        "OPTIONS": {
-            "charset": "utf8mb4",
-        },
     }
 }
 
+if DATABASES["default"]["ENGINE"].endswith("mysql"):
+    DATABASES["default"]["OPTIONS"] = {"charset": "utf8mb4"}
+
 AUTH_PASSWORD_VALIDATORS = [
     {"NAME": "django.contrib.auth.password_validation.UserAttributeSimilarityValidator"},
     {"NAME": "django.contrib.auth.password_validation.MinimumLengthValidator"},