Date detection and time

[teemue]

Hi!

If a date column in a CSV file contains time (e.g. "2025-04-30 09:20"), it's considered invalid, so currently the timestamp needs manual correction.

[dannymcc]

Fixed in #130 — parse_date_value now includes datetime-with-time formats (e.g. %Y-%m-%d %H:%M) for all format modes so timestamps in date columns are handled correctly.