Require configuration selectors only for applicable scopes

config.go

@@ -74,6 +74,7 @@ type ConfigScope[C any] struct {
 }
 
 // Selector binds one typed command flag to selected configuration scopes.
+// A required binding is required only when a selected scope uses it.
 type Selector[C any] struct {
 	Binding Flag[C]
 	Scopes  []string
@@ -101,6 +102,8 @@ type configScopesInput struct {
 }
 
 type selectorState[C any] struct {
+	name     string
+	required bool
 	scopes   []string
 	supplied bool
 	apply    func(*C)