Allow users to import historical transactions in bulk by uploading a CSV or spreadsheet file. This is especially useful when switching between data providers (e.g., from MX to Plaid) where the new provider only retrieves a limited history window, leaving a gap in older transaction data. Users who have downloaded or reformatted their historical transactions should be able to upload them directly rather than entering each one manually. The import flow could map common columns (date, amount, merchant, category) to Piere’s internal transaction format.