Excel Data Deduplication & Report

I have a dataset stored in several Excel/CSV files that needs a thorough scrub. My priority is to spot and remove every duplicate, validate the remaining records, and then document exactly what was changed. You are free to rely on Excel’s built-in tools, Power Query, Python (pandas), or any other workflow you find efficient—as long as the final result is clean, consistent data and a clear audit trail.

Here is what I need from you:
• Return a cleaned Excel/CSV file with all duplicates removed and any obvious data-entry issues fixed.
• Produce a concise cleanup report outlining the rules you applied, the number of records affected, and any assumptions made.

I will supply the original files once we start; you hand back the polished dataset and the report so I can file it for compliance. Let me know your preferred approach and estimated turnaround.