fix: make the test-profile generator hermetic and re-runnable

test_profile_init_integration failed on any machine with a generated test
profile already present. Two causes, both real bugs rather than test noise:

- scripts/generate_test_profile.py mutated constants.APP_DIR at import time
  to append "tests". The value was captured when constants was first
  imported -- long before a test can monkeypatch Path.home -- so the script
  read the developer's real ~/.seedpass/tests, and a reload appended another
  "tests" segment. The mutation also leaked into every other importer of
  constants in the same process. The tests directory is now derived per call
  from constants.APP_DIR instead.

- initialize_profile assumed add_fingerprint returns None for an existing
  profile, which is what its docstring still promises; it actually raises
  ValueError. Re-running the generator against an existing profile therefore
  crashed. It now treats "already exists" as the ordinary case.

test_profile_init_integration also repoints constants.APP_DIR so it no
longer depends on the developer's home directory, and
test_generate_test_profile asserts against the derived tests directory
rather than the mutated global.

Verified hermetic: the test passes repeatedly and touches nothing under the
real ~/.seedpass. Full Python suite: 1178 passed, 16 skipped, 0 failed.

Co-Authored-By: Claude Fable 5 <[email protected]>

src/tests/test_generate_test_profile.py

@@ -27,7 +27,14 @@ def test_initialize_profile_creates_directories(monkeypatch):
         seed, mgr, dir_path, fingerprint, cfg_mgr = gtp.initialize_profile("test")
         assert cfg_mgr is not None
 
-        assert constants.APP_DIR.exists()
-        assert (constants.APP_DIR / "test_seed.txt").exists()
+        # Generated profiles live under APP_DIR/tests so they never mix with
+        # real ones. The script used to achieve this by mutating
+        # constants.APP_DIR at import time, which leaked into every other
+        # importer in the process; it now derives the path per call.
+        test_dir = gtp.test_app_dir()
+        assert test_dir == constants.APP_DIR / "tests"
+        assert test_dir.exists()
+        assert (test_dir / "test_seed.txt").exists()
+        assert dir_path.parent == test_dir
         assert dir_path.exists()
         assert dir_path.name == fingerprint

src/tests/test_profile_init_integration.py

@@ -3,6 +3,7 @@ import importlib.util
 from pathlib import Path
 from tempfile import TemporaryDirectory
 
+import constants
 from seedpass.core.manager import PasswordManager, EncryptionMode
 
 
@@ -21,6 +22,11 @@ def test_initialize_profile_and_manager(monkeypatch):
     with TemporaryDirectory() as tmpdir:
         tmp_path = Path(tmpdir)
         monkeypatch.setattr(Path, "home", lambda: tmp_path)
+        # constants.APP_DIR is computed from Path.home() when constants is
+        # first imported, which happens long before this monkeypatch. Without
+        # repointing it the script reads the developer's real ~/.seedpass and
+        # fails against whatever profile happens to live there.
+        monkeypatch.setattr(constants, "APP_DIR", tmp_path / ".seedpass")
 
         gtp = load_script()