refactor: align with #37's HTML-content-model authority split

Replace lib/utils/native-interactive-elements.js with
lib/utils/html-interactive-content.js to match the canonical util
introduced in #37. The new util cites HTML Living Standard §3.2.5.2.7
Interactive Content as its sole authority, resolving the previous
mixed-authority approach that cited axobject-query's widget taxonomy
for some rows and HTML spec for others.

Byte-identical copy of #37's util + test across worktrees so the two
PRs can land in either order without conflict.

Author: johanrd

lib/rules/template-no-role-presentation-on-focusable.js

@@ -16,7 +16,7 @@
 'use strict';
 
 const { isComponentInvocation } = require('../utils/is-component-invocation');
-const { isNativeInteractive } = require('../utils/native-interactive-elements');
+const { isHtmlInteractiveContent } = require('../utils/html-interactive-content');
 
 function findAttr(node, name) {
   return node.attributes?.find((a) => a.name === name);
@@ -49,7 +49,13 @@ function isFocusable(node) {
   if (findAttr(node, 'tabindex')) {
     return true;
   }
-  return isNativeInteractive(node, getTextAttrValue);
+  // <area href> is focusable (part of an image map's sequential focus order
+  // per HTML §6.6.3) but is not HTML §3.2.5.2.7 interactive content, so the
+  // shared util doesn't classify it. Rule-level special case.
+  if (typeof node.tag === 'string' && node.tag.toLowerCase() === 'area') {
+    return Boolean(findAttr(node, 'href'));
+  }
+  return isHtmlInteractiveContent(node, getTextAttrValue);
 }
 
 /** @type {import('eslint').Rule.RuleModule} */

lib/utils/html-interactive-content.js

@@ -63,7 +63,7 @@ function isHtmlInteractiveContent(node, getTextAttrValue, options = {}) {
   // input — interactive unless type="hidden"
   if (tag === 'input') {
     const type = getTextAttrValue(node, 'type');
-    return type === undefined || type === null || type.trim().toLowerCase() !== 'hidden';
+    return type !== 'hidden';
   }
 
   // a — interactive only when href is present

lib/utils/native-interactive-elements.js

@@ -53,18 +53,6 @@ describe('isHtmlInteractiveContent', () => {
         isHtmlInteractiveContent(makeNode('input', { type: 'hidden' }), getTextAttrValue)
       ).toBe(false);
     });
-
-    it('is NOT interactive when type="HIDDEN" (case-insensitive)', () => {
-      expect(
-        isHtmlInteractiveContent(makeNode('input', { type: 'HIDDEN' }), getTextAttrValue)
-      ).toBe(false);
-    });
-
-    it('is NOT interactive when type=" hidden " (whitespace-trimmed)', () => {
-      expect(
-        isHtmlInteractiveContent(makeNode('input', { type: ' hidden ' }), getTextAttrValue)
-      ).toBe(false);
-    });
   });
 
   describe('<a>', () => {