Document shared debug input and reporting mode

flag_values.go

@@ -24,6 +24,8 @@ type FlagValues[I any] struct {
 // each adapted flag stores its prepared value in target, associated with the
 // original inner binding identity. Copies of an original handle remain
 // selectable; an independently constructed lookalike does not.
+// A captured debug BoolFlag shares reporting input as described by [BoolFlag];
+// its requiredness is checked when selected for application.
 func CaptureFlags[Outer, I any](flags []Flag[I], target func(*Outer) *FlagValues[I]) []Flag[Outer] {
 	captured := make([]Flag[Outer], len(flags))
 	for index, original := range flags {