Fix a11y icon, FAB label colors, add high-contrast stylesheet, sync theme vars

- Fix faIcon() to use <i> elements (FA7 compatibility)
- Fix #mokoThemeFab .label and button colors to white (visible on
  both light and dark themes)
- Fix font-weight typo (600px → 600)
- Add --footer-padding-* variables to all 6 theme files
- Create a11y-high-contrast.css with WCAG AAA contrast ratios for
  both light and dark modes
- Register high-contrast stylesheet in joomla.asset.json
- Lazy-load high-contrast CSS when a11y contrast toggle is activated

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/media/js/template.js

@@ -229,6 +229,18 @@
 
 	function applyContrast(on) {
 		root.classList.toggle("a11y-high-contrast", on);
+		// Lazy-load the high-contrast stylesheet
+		var hcId = "mokoA11yHcSheet";
+		var existing = doc.getElementById(hcId);
+		if (on && !existing) {
+			var link = doc.createElement("link");
+			link.id = hcId;
+			link.rel = "stylesheet";
+			link.href = (doc.querySelector('link[href*="mokocassiopeia/css/template"]') || {}).href
+				? (doc.querySelector('link[href*="mokocassiopeia/css/template"]').href.replace(/\/css\/template[^/]*$/, "/css/a11y-high-contrast.css"))
+				: "media/templates/site/mokocassiopeia/css/a11y-high-contrast.css";
+			doc.head.appendChild(link);
+		}
 	}
 
 	function applyLinks(on) {
@@ -245,10 +257,10 @@
 
 	/** Create a Font Awesome icon element (safe DOM, no innerHTML). */
 	function faIcon(classes) {
-		var span = doc.createElement("span");
-		span.className = classes;
-		span.setAttribute("aria-hidden", "true");
-		return span;
+		var i = doc.createElement("i");
+		i.className = classes;
+		i.setAttribute("aria-hidden", "true");
+		return i;
 	}
 
 	function buildA11yToolbar() {