Watch tables (VAT) in the app

Done: list of tables, row editor (name, display format, modify value, comment), generator and push to TIA.

What we learned: the display format must be one of the values TIA knows, and export fails on an inconsistent table — handy as a check after import.

Fix: TIA V17 rejected a row with the "Default" format. A row without a format now sends no format at all, and TIA picks one from the data type.