fix(template-require-context-role): broaden hasAriaHiddenTrue via classifyAttribute (rows h3, h7, h12, h14)

Before:
- `hasAriaHiddenTrue` matched only `aria-hidden="true"` as a `GlimmerTextNode`.
- Mustache forms that render the same `aria-hidden="true"` at runtime were
  silently treated as visible:
    - `aria-hidden={{"true"}}` (h7) → renders `aria-hidden="true"`
    - `aria-hidden="{{true}}"`  (h12) → renders `aria-hidden="true"`
    - `aria-hidden="{{'true'}}"` (h14) → renders `aria-hidden="true"`
- Each was a false positive: a child with role="treeitem" inside a hidden
  ancestor was reported as missing-context, even though the entire subtree
  is hidden from assistive tech and "context" is moot.

After:
- `hasAriaHiddenTrue` flows through `classifyAttribute` from the new util.
  The check is `presence === 'present' && value === 'true'`, which matches
  exactly h3 / h7 / h12 / h14 — every source form whose IDL `ariaHidden` is
  `"true"`.
- Note: h5 (bare `{{true}}`) renders `aria-hidden=""` (contested per ARIA
  spec), so `classifyAttribute` returns `value=""` for that form and the
  equality check correctly excludes it. The rule deliberately does not
  treat the contested empty-value case as hidden.

Test additions in both GJS and HBS suites:
- Valid: `<div aria-hidden={{"true"}} role="tablist"><div role="treeitem">…`
- Valid: `<div aria-hidden="{{true}}" role="tablist"><div role="treeitem">…`
- Valid: `<div aria-hidden="{{'true'}}" role="tablist"><div role="treeitem">…`

111 tests pass. Doc rows cited: h3 (existing), h7, h12, h14.

Author: johanrd

lib/rules/template-require-context-role.js

@@ -1,3 +1,7 @@
+'use strict';
+
+const { classifyAttribute } = require('../utils/glimmer-attr-presence');
+
 const ROLES_REQUIRING_CONTEXT = {
   cell: ['row'],
   listitem: ['group', 'list'],
@@ -89,9 +93,18 @@ function getRoleFromNode(node) {
   return null;
 }
 
+// Recognize every source form that renders `aria-hidden="true"` at runtime
+// per the verified model (doc rows h3, h7, h12, h14). The previous
+// `GlimmerTextNode + chars === 'true'` check missed bare `{{"true"}}` and
+// concat forms `"{{true}}"` / `"{{'true'}}"` — all three render identical
+// HTML and are interpreted as "hidden" by every assistive tech. Notably,
+// bare `{{true}}` is *not* hidden (h5: renders `aria-hidden=""`, contested
+// per ARIA spec) — `classifyAttribute` returns value="" for that case so
+// the equality check correctly excludes it.
 function hasAriaHiddenTrue(node) {
   const attr = node.attributes?.find((a) => a.name === 'aria-hidden');
-  return attr?.value?.type === 'GlimmerTextNode' && attr.value.chars === 'true';
+  const { presence, value } = classifyAttribute(attr);
+  return presence === 'present' && value === 'true';
 }
 
 /**

tests/lib/rules/template-require-context-role.js

@@ -56,6 +56,14 @@ ruleTester.run('template-require-context-role', rule, {
     '<template><div role="rowgroup"><div role="row">Item One</div></div></template>',
     '<template><div role="treegrid"><div role="row">Item One</div></div></template>',
     '<template><div aria-hidden="true" role="tablist"><div role="treeitem">Item One</div></div></template>',
+    // Mustache forms that render `aria-hidden="true"` at runtime (doc rows
+    // h7, h12, h14) — were previously false-positive flagged because the
+    // rule only matched the static text node. classifyAttribute resolves
+    // each form to value="true" and the parent is correctly recognized as
+    // hidden, suppressing the missing-context check.
+    '<template><div aria-hidden={{"true"}} role="tablist"><div role="treeitem">Item</div></div></template>',
+    '<template><div aria-hidden="{{true}}" role="tablist"><div role="treeitem">Item</div></div></template>',
+    '<template><div aria-hidden="{{\'true\'}}" role="tablist"><div role="treeitem">Item</div></div></template>',
     '<template><div role="grid"><div role="rowgroup">Item One</div></div></template>',
     '<template><div role="row"><div role="rowheader">Item One</div></div></template>',
     '<template><div role="tablist"><div role="tab">Item One</div></div></template>',
@@ -321,6 +329,10 @@ hbsRuleTester.run('template-require-context-role', rule, {
     '<div role="rowgroup"><div role="row">Item One</div></div>',
     '<div role="treegrid"><div role="row">Item One</div></div>',
     '<div aria-hidden="true" role="tablist"><div role="treeitem">Item One</div></div>',
+    // Mustache forms that render `aria-hidden="true"` at runtime (doc rows h7, h12, h14)
+    '<div aria-hidden={{"true"}} role="tablist"><div role="treeitem">Item</div></div>',
+    '<div aria-hidden="{{true}}" role="tablist"><div role="treeitem">Item</div></div>',
+    '<div aria-hidden="{{\'true\'}}" role="tablist"><div role="treeitem">Item</div></div>',
     '<div role="grid"><div role="rowgroup">Item One</div></div>',
     '<div role="row"><div role="rowheader">Item One</div></div>',
     '<div role="tablist"><div role="tab">Item One</div></div>',