test: change dataset and retrain

[ypang-neuraco]

Features

• Create an integration test that validates dataset mutation, dataset statistics, datatype handling, and training correctness.
• Covers initial collection, statistics verification, baseline overfitting, dataset mutation, retraining, and corrupted ablation proving all modalities are used.
• Integration test to cover synchronise -> mutate dataset -> synchronise
• Set wait=True for stop_recording
• Remove constants.py

Items

• NCRL-605