build: cleanup for new selenium and guards

tests/test_settings.py

@@ -1,7 +1,16 @@
+import os
+
 from smileyface.settings import AppSettings
 
 
-def test_defaults():
+def _clear_smileyface_env(monkeypatch):
+    for key in list(os.environ):
+        if key.startswith("SMILEYFACE_"):
+            monkeypatch.delenv(key, raising=False)
+
+
+def test_defaults(monkeypatch):
+    _clear_smileyface_env(monkeypatch)
     settings = AppSettings(_env_file=None)
     assert settings.sqlite_filename == "smiles.db"
     assert settings.skip_validate is False
@@ -9,6 +18,7 @@ def test_defaults():
 
 
 def test_env_overrides(monkeypatch):
+    _clear_smileyface_env(monkeypatch)
     monkeypatch.setenv("SMILEYFACE_PROJECT_DIR", "/srv/ut4")
     monkeypatch.setenv("SMILEYFACE_SKIP_VALIDATE", "true")
     settings = AppSettings(_env_file=None)