test: derive keys for vault setup

src/tests/test_seed_import.py

@@ -1,7 +1,8 @@
 import sys
 from pathlib import Path
 from tempfile import TemporaryDirectory
-from cryptography.fernet import Fernet
+from helpers import TEST_PASSWORD
+from utils.key_derivation import derive_key_from_password
 from mnemonic import Mnemonic
 
 sys.path.append(str(Path(__file__).resolve().parents[1]))
@@ -12,7 +13,7 @@ from password_manager.manager import PasswordManager
 
 def test_seed_encryption_round_trip():
     with TemporaryDirectory() as tmpdir:
-        key = Fernet.generate_key()
+        key = derive_key_from_password(TEST_PASSWORD)
         enc_mgr = EncryptionManager(key, Path(tmpdir))
 
         seed = Mnemonic("english").generate(strength=128)