New features

onProgress callback option — fires on every setprogress call with the current value (0–100)
animationDuration option (default 0.6) and animationEasing option (default 'ease') — animation timing is no
longer hardcoded
ARIA accessibility: overlay (or img in filter mode) automatically gets role="progressbar", aria-valuemin,
aria-valuemax, and aria-valuenow kept in sync; configurable via new ariaLabel option (default 'Loading')
TypeScript declarations for both vanilla (LoadgoOptions, LoadgoAPI) and jQuery (typed loadgo() overloads) — no
@types/* needed

Bug fixes

Memory leak: window resize listener was never removed; it is now properly cleaned up on destroy()
destroy() in filter mode now removes ARIA attributes it added to the image
Vendor prefix -webkit-filter replaced with standard filter throughout

Resize handler throttled via requestAnimationFrame (~60 fps cap) and transition is stripped during resize then
restored 150 ms after the last resize event, preventing janky animations
extend() in the vanilla build now uses Object.assign instead of JSON.parse/JSON.stringify, correctly handling
function values (e.g. resize, onProgress)
Added CONTRIBUTING.md with dev setup, build, test, lint, commit, and release instructions

44 new tests added (136 total, up from 92) covering re-initialization, loop/stop in filter mode, resize listener
cleanup, ARIA attributes, onProgress, and custom animation timing