Oktoreno/merged-some-sheets-to-one-sheet — reverse-engineered prompt

Build me a simple Python tool that takes an Excel file with multiple worksheets and combines the rows from selected sheets into one new worksheet. I want it to be easy for a normal person to run: ask for the input file, let me choose whether to merge all sheets or only some sheet names, and save a new Excel file without changing the original.

Please keep the header row clean so repeated headers from each sheet don't get copied over, and make sure blank rows don't break anything. If sheets have slightly different columns, include all columns and leave empty cells where data is missing. Add clear messages while it runs, simple error handling for missing files or bad sheet names, and a short usage note so I know what to type.

Use Python and look up current docs online if you need to.