fix: ignore compose-only runtime variables

backend/tests/test_settings_validation.py

@@ -66,3 +66,13 @@ def test_enabled_wecom_delivery_requires_all_credentials():
 
     with pytest.raises(ValueError, match="WECOM"):
         validate_runtime_settings(settings)
+
+
+def test_ignores_compose_only_environment_fields():
+    settings = Settings(
+        environment="test",
+        postgres_password="compose-only",
+        pingwatch_backend_bind="127.0.0.1:18065",
+    )
+
+    assert settings.environment == "test"