fix: use ColorGroup enum and disable dark palette via QT_STYLE_OVERRIDE

Makefile

@@ -92,7 +92,7 @@ ast:
 	else \
 		echo "=> extracted wavs exist ($$OUT/$${STEM_A}_audio.wav, $$OUT/$${STEM_B}_audio.wav), skipping extract"; \
 	fi
-	@if [ -x $(PY) ]; then $(PY) sync_audio_test.py --config $(CONFIG); else python3 sync_audio_test.py --config $(CONFIG); fi
+	@if [ -x $(PY) ]; then QT_STYLE_OVERRIDE=Fusion $(PY) sync_audio_test.py --config $(CONFIG); else QT_STYLE_OVERRIDE=Fusion python3 sync_audio_test.py --config $(CONFIG); fi
 
 clean:
 	rm -rf $(VENV) __pycache__ .pytest_cache