fix(template-interactive-supports-focus): apply tabindex carve-outs to contenteditable (Copilot review)

Mirror the disabled/hidden-input guard already on the tabindex branch:
the UA ignores contenteditable on disabled form controls and on
<input type='hidden'> just as it ignores tabindex, so contenteditable
must not count as satisfying the focus requirement in those cases.

Author: johanrd

lib/rules/template-interactive-supports-focus.js

@@ -219,9 +219,20 @@ module.exports = {
           }
         }
 
-        // contenteditable also makes an element focusable.
+        // contenteditable also makes an element focusable, with the same
+        // HTML-spec carve-outs as tabindex: the UA ignores it on disabled
+        // form controls (HTML §4.10.18.5) and on <input type="hidden">
+        // (no rendered element to edit), so the a11y conflict still stands.
         if (isContentEditable(node)) {
-          return;
+          const disabled = DISABLABLE_FORM_CONTROLS.has(tag) && findAttr(node, 'disabled');
+          let hiddenInput = false;
+          if (tag === 'input') {
+            const type = getTextAttrValue(findAttr(node, 'type'));
+            hiddenInput = typeof type === 'string' && type.trim().toLowerCase() === 'hidden';
+          }
+          if (!disabled && !hiddenInput) {
+            return;
+          }
         }
 
         context.report({