fix: add oklch() color support for html2canvas compatibility

Tailwind v4 uses oklch() colors by default that causes the  html2canvas to throws an error
when it encounters oklch() because it does not support that color function.

Fix: before passing the container to html2canvas, walk all elements and
resolve any oklch() computed style values to rgb using a canvas 2D context
(native browser color conversion), then write them back as inline styles

Author: 2iaad

src/worker.js

@@ -23,7 +23,7 @@ function resolveOklchColors(container) {
     var computed = getComputedStyle(el);
     colorProps.forEach(function (prop) {
       var val = computed.getPropertyValue(prop);
-      if (val && val.indexOf('oklch') !== -1) {
+      if (val && val.toLowerCase().indexOf('oklch') !== -1) {
         ctx.fillStyle = val;
         el.style.setProperty(prop, ctx.fillStyle);
       }