Integration (verdict fix, PR #2808 in the batch): kept one set_carrying and one frame.rs call; carrying is pub(crate); only the text_field.rs hunk plus tests and docs come from this PR.
crates/ui-egui/src/widgets.rs: kept HEAD's doc comment and pub(crate) fn carrying. crates/ui-egui/src/tests.rs: both test modules. docs: union.