Answer architecture round 3, stability round 1 and product-owner round 1: CalcName and proven.OfCalc for one meaning per name, a lazy load placed where its lookup found it, DataType's constants typed under it, and cover printing the module's total

calc.go

@@ -26,7 +26,7 @@ func checkCalcFields(args []string, fields map[string]node) error {
 // checkCalcNames holds each calc of t reading a name to the checks checkCalcFields makes of a field.
 func checkCalcNames(path string, t *template) error {
 	for _, o := range t.compiled.ops {
-		if o.Fn != builtinfunc.Calc || !slices.ContainsFunc(o.operands, func(a arm) bool { return a.kind == namedRead }) {
+		if o.Fn != builtinfunc.CalcName || !slices.ContainsFunc(o.operands, func(a arm) bool { return a.kind == namedRead }) {
 			continue
 		}
 		if err := checkOperands(o.Args[0], builtinfunc.ParsedCalc(o.Args[0]), operandNodes(o)); err != nil {