Configurable fields that survive being renamed

The use case

“Let an admin add a new field without a developer touching the schema.” Fields are defined in configuration tables and the values are stored as a versioned JSON blob in a single text column.

The two key decisions

• A stable key per field (an autonumber column, jts_fieldkey). The JSON stores { fieldKey, definitionId, label, type, value } and matches saved values by that key, not by the label. Renaming a field never loses data.
• Options as id=label, one per line:

1=Commercial
2=Private
3=Other

The id is saved, not the text. Fixing a typo in a label never invalidates historical data.

Bonus

Every table and column name the control uses is a configurable property, so it can be reused with a different schema without recompiling.