Generating Custom Field

This handles the gnarly parts of Salesforce Custom Field metadata generation, specifically the stuff that breaks during deployment. It knows the difference between Master-Detail and Lookup relationships (Master-Detail fields can't have required tags or deleteConstraint, which trips people up constantly), enforces the right precision and scale rules for numbers, and gets Roll-up Summary field format correct. The mandatory description and inlineHelpText requirements are opinionated but prevent lazy field documentation. Use this when you're generating field XML and want to avoid the back-and-forth with deployment errors. It's built around the actual Metadata API constraints, not just what works in the UI.