feat: platform-dependent config path (APPDATA on Windows)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/test_config.py

@@ -1,4 +1,6 @@
 from pathlib import Path
+from unittest.mock import patch
+import os
 import tomllib
 
 from whisper_local.config import Config, load_config
@@ -57,3 +59,20 @@ class TestLoadConfig:
         config_file.write_text("")
         config = load_config(config_file)
         assert config.hotkey == "KEY_F12"
+
+
+class TestConfigPath:
+    @patch.dict(os.environ, {"APPDATA": "C:\\Users\\test\\AppData\\Roaming"})
+    @patch("whisper_local.config.sys")
+    def test_windows_config_path(self, mock_sys):
+        mock_sys.platform = "win32"
+        from whisper_local.config import _default_config_path
+        result = _default_config_path()
+        assert result == Path("C:\\Users\\test\\AppData\\Roaming") / "whisper-local" / "config.toml"
+
+    @patch("whisper_local.config.sys")
+    def test_linux_config_path(self, mock_sys):
+        mock_sys.platform = "linux"
+        from whisper_local.config import _default_config_path
+        result = _default_config_path()
+        assert result == Path.home() / ".config" / "whisper-local" / "config.toml"