tests: add offline default and kdf slider

src/tests/test_kdf_strength_slider.py

@@ -0,0 +1,19 @@
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from types import SimpleNamespace
+
+from helpers import create_vault, TEST_SEED, TEST_PASSWORD
+from seedpass.core.config_manager import ConfigManager
+from main import handle_set_kdf_iterations
+
+
+def test_kdf_strength_slider_persists(monkeypatch):
+    with TemporaryDirectory() as tmpdir:
+        tmp_path = Path(tmpdir)
+        vault, enc_mgr = create_vault(tmp_path, TEST_SEED, TEST_PASSWORD)
+        cfg_mgr = ConfigManager(vault, tmp_path)
+        pm = SimpleNamespace(config_manager=cfg_mgr)
+        inputs = iter(["3"])
+        monkeypatch.setattr("builtins.input", lambda *_: next(inputs))
+        handle_set_kdf_iterations(pm)
+        assert cfg_mgr.get_kdf_iterations() == 100_000