feat: add config module with TOML loading and defaults

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

tests/test_config.py

@@ -0,0 +1,59 @@
+from pathlib import Path
+import tomllib
+
+from whisper_local.config import Config, load_config
+
+
+class TestConfigDefaults:
+    def test_default_hotkey(self):
+        config = Config()
+        assert config.hotkey == "KEY_F12"
+
+    def test_default_whisper_model(self):
+        config = Config()
+        assert config.whisper_model == "small"
+
+    def test_default_language(self):
+        config = Config()
+        assert config.language == "de"
+
+    def test_default_compute_type(self):
+        config = Config()
+        assert config.compute_type == "int8"
+
+    def test_default_sample_rate(self):
+        config = Config()
+        assert config.sample_rate == 16000
+
+    def test_default_channels(self):
+        config = Config()
+        assert config.channels == 1
+
+    def test_default_min_duration(self):
+        config = Config()
+        assert config.min_duration == 0.5
+
+
+class TestLoadConfig:
+    def test_load_from_toml(self, tmp_path):
+        config_file = tmp_path / "config.toml"
+        config_file.write_text(
+            '[hotkey]\nkey = "KEY_F8"\n\n'
+            '[whisper]\nmodel = "tiny"\nlanguage = "en"\n'
+        )
+        config = load_config(config_file)
+        assert config.hotkey == "KEY_F8"
+        assert config.whisper_model == "tiny"
+        assert config.language == "en"
+        # Defaults bleiben erhalten
+        assert config.compute_type == "int8"
+
+    def test_load_nonexistent_returns_defaults(self, tmp_path):
+        config = load_config(tmp_path / "nope.toml")
+        assert config.hotkey == "KEY_F12"
+
+    def test_load_empty_file(self, tmp_path):
+        config_file = tmp_path / "config.toml"
+        config_file.write_text("")
+        config = load_config(config_file)
+        assert config.hotkey == "KEY_F12"