feat(dev): development pages for testing and prototypes

assets/js/pages/devcolors.js

@@ -0,0 +1,7 @@
+document.querySelector('#accent-color-hue').addEventListener('change', (e) => {
+	// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+	const hue = /** @type {number} */ (e.target?.value);
+
+	document.querySelector('body')
+		.setAttribute('style', `--user-theme-accent-hue:${String(hue)};`);
+});