Add TDMS support and data pipeline helpers

[vudxlab]

Summary

• add shared pipeline functions in process_data for discovering files, loading .mat/.tdms data, processing, and visualization
• support TDMS channel extraction alongside existing MATLAB loader and ensure mixed datasets are handled
• simplify main to minimal CLI that delegates to the new pipeline interfaces

Testing

• Not run (not requested)

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Handle missing TDMS dependency gracefully

The module now imports TdmsFile unconditionally, so python main.py or any .mat-only workflow will raise ModuleNotFoundError: No module named 'nptdms' on environments that only had the previous MATLAB dependencies. TDMS support was added as an optional feature, but this import makes it a hard requirement and breaks existing usage unless users install an extra package first. Guard the import or defer it until a .tdms file is actually processed so .mat runs continue to work.

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