dates not detected in arrow tables

[Fil]

A bug where dates are shown as numbers in the table; it should have been covered by #263, but in this case we have field.type.unit==0 instead of 1.

The bug can be seen in Framework with the following page:

---
sql:
  launches: data/launches.csv
---

# Rocket launches 🚀

```sql echo
SELECT * FROM launches;
```

I can't find the documentation for what this "unit 0" means. The source code https://github.com/apache/arrow/blob/main/js/src/fb/time.ts seems to indicate that these are seconds. If I change

inputs/src/table.js

Line 389 in 7ae53c7

return field.type.unit === 1 ? "date" : "number"; // millisecond

to accept 0 as a date, the dates appear correctly in the table.