createFolderGallery accepts an onSelect callback, but the equivalent for navigation is event-only (fg-activechange). Add an onActiveChange(index, item) option to the core for parity, wire it through the element / React / Vue wrappers, update the .d.ts files and the README API table, and add a test. CONTRIBUTING.md lists every place a new option has to touch.
createFolderGallery accepts an onSelect callback, but the equivalent for navigation is event-only (fg-activechange). Add an onActiveChange(index, item) option to the core for parity, wire it through the element / React / Vue wrappers, update the .d.ts files and the README API table, and add a test. CONTRIBUTING.md lists every place a new option has to touch.