Save a field definition and its rules
What It Does
The editor saves a field definition before its complete rules. Reordering properties likewise uses a sequence of independent replacements.
The Flow
When Something Fails
Report that the field saved but its rules did not; do not undo the definition. The field has its new definition with earlier rules, or no rules after creation. Roll back the rule change on invalid input. Any preceding definition save remains committed. Refuse enabling uniqueness until duplicates are resolved, preserving existing rules. The uniqueness change and reservation rebuild cannot partially commit. Stop the sequence at the first rejected replacement and display the error. Earlier property positions remain saved; later ones retain preceding values.
Open Design Questions
Andrew should decide whether field definitions and rules need one composite operation.