Add container diarization configuration

tests/test_application_config.py

@@ -28,3 +28,41 @@ def test_settings_accept_valid_native_configuration(tmp_path: Path) -> None:
     settings = AppSettings(data_root=tmp_path / "runs", whisper_model=model)
 
     settings.validate_for_processing()
+
+    assert settings.diarization_runtime == "native"
+    assert settings.diarization_container_args == ()
+
+
+def test_environment_defaults_to_no_diarization_container_args(monkeypatch) -> None:
+    monkeypatch.delenv("MKA_DIARIZATION_CONTAINER_ARGS", raising=False)
+
+    settings = AppSettings.from_environment()
+
+    assert settings.diarization_container_args == ()
+
+
+def test_environment_parses_multiple_ordered_container_args(monkeypatch) -> None:
+    monkeypatch.setenv(
+        "MKA_DIARIZATION_CONTAINER_ARGS",
+        '["--device=/dev/kfd", "--device=/dev/dri", "--group-add", "video"]',
+    )
+
+    settings = AppSettings.from_environment()
+
+    assert settings.diarization_container_args == (
+        "--device=/dev/kfd",
+        "--device=/dev/dri",
+        "--group-add",
+        "video",
+    )
+
+
+@pytest.mark.parametrize(
+    "value",
+    ["not-json", '"--flag"', '["valid", ""]', '["valid", 1]'],
+)
+def test_environment_rejects_invalid_container_args(monkeypatch, value: str) -> None:
+    monkeypatch.setenv("MKA_DIARIZATION_CONTAINER_ARGS", value)
+
+    with pytest.raises(ConfigurationError, match="JSON array"):
+        AppSettings.from_environment()