fix: preserve settings save errors

README.md

@@ -1,6 +0,0 @@
-# Voice Transcriptor
-
-The editable default transcription model is `gpt-4o-transcribe`. New installations use
-Brazilian Portuguese (`pt-BR`) and save output to the user's Documents folder when it is
-available, otherwise to the home folder. API keys are stored only in the operating-system
-keyring and are never written to the settings file.

src/voice_transcriptor/services/settings.py

@@ -66,7 +66,10 @@ class SettingsRepository:
             raise SettingsError("Unable to save settings.") from exc
         finally:
             if temporary_path is not None and temporary_path.exists():
-                temporary_path.unlink(missing_ok=True)
+                try:
+                    temporary_path.unlink(missing_ok=True)
+                except OSError:
+                    pass
 
     @staticmethod
     def _settings_from_payload(payload: object) -> AppSettings:

tests/test_settings.py

@@ -4,7 +4,7 @@ from pathlib import Path
 import pytest
 
 from voice_transcriptor.models import AppSettings
-from voice_transcriptor.services.settings import SettingsRepository
+from voice_transcriptor.services.settings import SettingsError, SettingsRepository
 
 
 def test_load_missing_file_returns_documented_defaults(monkeypatch, tmp_path: Path) -> None:
@@ -78,6 +78,27 @@ def test_save_replaces_existing_file_atomically(monkeypatch, tmp_path: Path) ->
     assert json.loads(path.read_text(encoding="utf-8"))["model"] == "model"
 
 
+def test_save_preserves_settings_error_when_replace_and_cleanup_fail(
+    monkeypatch, tmp_path: Path
+) -> None:
+    path = tmp_path / "settings.json"
+    replacement_failure = OSError("target is locked")
+
+    def failing_replace(source: Path, destination: Path) -> Path:
+        raise replacement_failure
+
+    def failing_unlink(path: Path, missing_ok: bool = False) -> None:
+        raise OSError("temporary file is locked")
+
+    monkeypatch.setattr(Path, "replace", failing_replace)
+    monkeypatch.setattr(Path, "unlink", failing_unlink)
+
+    with pytest.raises(SettingsError) as caught:
+        SettingsRepository(path).save(AppSettings("model", "pt-BR", tmp_path / "out"))
+
+    assert caught.value.__cause__ is replacement_failure
+
+
 def test_saved_settings_never_include_api_key_fields(tmp_path: Path) -> None:
     path = tmp_path / "settings.json"