Build an editor on Flutter Web. The user opens budget.csv , edits it, hits save. They get budget.csv in their Downloads folder. They edit again, save again: budget (1).csv . Again: budget (2).csv . Their real file — the one on their Desktop that they opened — has never been touched. By the end of an afternoon they have nine numbered copies and no idea which is current. This is not a Flutter problem; it is what "saving" has meant on the web for twenty years. The browser hands yo...