Flag missing video files without dropping CSV rows

I'm planning a KNIME workflow to check a CSV containing `clip_id` and `file_path`. The video candidates would be downloaded manually from MiniMax H3, an independent third-party site I am associated with. Some files might later be moved, leaving outdated paths in the CSV.

I'd like to check each local path and retain every original row, adding a status such as `exists` or `missing`. I'd also like a separate table of missing files so I can locate them or update their paths manually. A missing file should leave its CSV record available for review rather than stop the check or remove the row.

Which nodes or workflow pattern would suit this, while preserving the original columns and `clip_id` values?