fix(html-interactive-content): use classifyAttribute for controls (cross-attr m6/d3 analog)

`controls` on `<audio>`/`<video>` is an HTML boolean attribute, so per the
cross-attribute observation in docs/glimmer-attribute-behavior.md, bare
`{{false}}` / `{{null}}` / `{{undefined}}` cause Glimmer to omit the
attribute at runtime. The helper's previous AST-presence check
(hasAttribute) treated `<video controls={{false}}>` as still having
controls — a false positive that propagated to every rule using
isHtmlInteractiveContent: nested-interactive, no-noninteractive-tabindex,
interactive-supports-focus, click-events-have-key-events, etc.

After:
- `controls` flows through classifyAttribute. Bare-mustache falsy literals
  now correctly classify as 'absent' → element is NOT interactive at
  runtime.
- `href` and `usemap` continue to use AST-presence — those are plain
  string attributes that don't falsy-coerce (i4 analog: bare `{{false}}`
  on a plain string renders as the literal `"false"`, attribute kept).

Concat forms (`controls="{{X}}"`) still classify as 'present' because
concat is never falsy at runtime — so the existing pass-through behavior
for concat is preserved.

Tests:
- New: `<video controls={{false}}>` → not interactive (regression-locking).
- New: `<audio controls={{null}}>` → not interactive.
- New: `<video controls="{{false}}">` → IS interactive (concat sets IDL
  true regardless of inner literal).
- All 9555 existing tests pass — no rule was relying on the buggy
  behavior, so this fix lands cleanly across all consumers.

Author: johanrd

lib/utils/html-interactive-content.js

@@ -1,5 +1,7 @@
 'use strict';
 
+const { classifyAttribute } = require('./glimmer-attr-presence');
+
 /**
  * HTML "interactive content" classification, authoritative per
  * [HTML Living Standard §3.2.5.2.7 Interactive content]
@@ -79,9 +81,18 @@ function isHtmlInteractiveContent(node, getTextAttrValue, options = {}) {
     return hasAttribute(node, 'usemap');
   }
 
-  // audio / video — interactive only when controls is present
+  // audio / video — interactive only when controls is present.
+  //
+  // `controls` is an HTML boolean attribute, so `controls={{false}}` /
+  // `{{null}}` / `{{undefined}}` cause Glimmer to omit the attribute at
+  // runtime (rows m6, m9, m10 by attribute-kind analogy + cross-attribute
+  // observation in docs/glimmer-attribute-behavior.md). AST-presence is
+  // wrong here — use classifyAttribute so the runtime presence drives the
+  // answer. `href` / `usemap` are plain string attrs that don't falsy-coerce
+  // (i4 analog), so AST-presence remains correct for them.
   if (tag === 'audio' || tag === 'video') {
-    return hasAttribute(node, 'controls');
+    const controlsAttr = node.attributes?.find((a) => a.name === 'controls');
+    return classifyAttribute(controlsAttr).presence === 'present';
   }
 
   return false;

tests/lib/utils/html-interactive-content-test.js

@@ -111,6 +111,61 @@ describe('isHtmlInteractiveContent', () => {
     it('<video> without controls is NOT interactive', () => {
       expect(isHtmlInteractiveContent(makeNode('video'), getTextAttrValue)).toBe(false);
     });
+
+    // Bare-mustache falsy on `controls` (per cross-attribute observation in
+    // docs/glimmer-attribute-behavior.md) causes Glimmer to omit the attribute
+    // at runtime — so `<video controls={{false}}>` has NO controls and is not
+    // interactive. Was previously a false positive: AST-presence treated it
+    // as having controls.
+    it('<video controls={{false}}> is NOT interactive (Glimmer omits the attribute)', () => {
+      const node = {
+        tag: 'video',
+        attributes: [
+          {
+            name: 'controls',
+            value: {
+              type: 'GlimmerMustacheStatement',
+              path: { type: 'GlimmerBooleanLiteral', value: false },
+            },
+          },
+        ],
+      };
+      expect(isHtmlInteractiveContent(node, getTextAttrValue)).toBe(false);
+    });
+
+    it('<audio controls={{null}}> is NOT interactive', () => {
+      const node = {
+        tag: 'audio',
+        attributes: [
+          {
+            name: 'controls',
+            value: { type: 'GlimmerMustacheStatement', path: { type: 'GlimmerNullLiteral' } },
+          },
+        ],
+      };
+      expect(isHtmlInteractiveContent(node, getTextAttrValue)).toBe(false);
+    });
+
+    it('<video controls="{{false}}"> IS interactive (concat sets IDL true regardless)', () => {
+      const node = {
+        tag: 'video',
+        attributes: [
+          {
+            name: 'controls',
+            value: {
+              type: 'GlimmerConcatStatement',
+              parts: [
+                {
+                  type: 'GlimmerMustacheStatement',
+                  path: { type: 'GlimmerBooleanLiteral', value: false },
+                },
+              ],
+            },
+          },
+        ],
+      };
+      expect(isHtmlInteractiveContent(node, getTextAttrValue)).toBe(true);
+    });
   });
 
   describe('elements NOT in §3.2.5.2.7', () => {