test(template-require-iframe-title): absorb audit-fixture cases, drop audit fixture

Upstream maintainers don't want the per-PR `tests/audit/peer-parity`
pattern — it's conceptual overhead for a narrow BUGFIX, requires a
parallel vitest config to keep out of the default suite, and reads as
documentation rather than executable coverage.

Port the one assertion from the iframe-title audit fixture that wasn't
already covered by the regular suite — `<iframe title={{""}} />` as
a documented under-flag — into the regular test file with an inline
comment explaining the divergence. All other audit cases were either
already covered or pure peer-plugin restatements without unique signal.

Drop:
- `tests/audit/iframe-title/peer-parity.js`
- `tests/audit/vitest.audit.config.mjs` (the parallel config)
- `tests/audit/**` exclusion in `vitest.config.mjs`
- `test:audit` script in `package.json`

Diff vs origin/master is now purely the rule fix, rule tests, and docs.

Author: johanrd

package.json

@@ -56,7 +56,6 @@
     "lint:remote": "eslint-remote-tester",
     "start": "pnpm test:watch",
     "test": "vitest run",
-    "test:audit": "vitest run --config=tests/audit/vitest.audit.config.mjs",
     "test:coverage": "vitest --coverage",
     "test:watch": "vitest",
     "update": "node ./scripts/update-rules.js && node ./scripts/list-jquery-methods.js && npm-run-all update:eslint-docs",

tests/audit/iframe-title/peer-parity.js

@@ -17,6 +17,13 @@ ruleTester.run('template-require-iframe-title', rule, {
     '<template><iframe title={{someValue}} /></template>',
     '<template><iframe title="" aria-hidden /></template>',
     '<template><iframe title="" hidden /></template>',
+    // Documented divergence — `title={{""}}` is not flagged. jsx-a11y catches
+    // empty-string literals via getLiteralPropValue; our rule inspects only
+    // the named literal AST nodes (Boolean / Null / Undefined / Number) and
+    // an empty-string mustache parses as a concat-of-nothing rather than a
+    // GlimmerStringLiteral, so the under-flag is structural rather than
+    // policy. Pinning the current behavior so any change is intentional.
+    '<template><iframe title={{""}} /></template>',
     '<template><iframe title="foo" /><iframe title="bar" /></template>',
     // allowWhitespaceOnlyTitle: true — whitespace-only accepted.
     {

tests/audit/vitest.audit.config.mjs

@@ -5,18 +5,7 @@ export default defineConfig({
     globals: true,
     setupFiles: [],
     include: ['**/tests/**/*.js'],
-    exclude: [
-      'tests/helpers/**',
-      'tests/bench/**',
-      'tests/fixtures/**',
-      // Audit fixtures are opt-in regression records — translate peer-plugin
-      // test cases to pin our CURRENT behavior / capture divergences. They
-      // live outside the default test run so the suite stays focused on the
-      // rule-level tests. Run them explicitly via:
-      //   pnpm exec vitest run tests/audit/**/*.js
-      'tests/audit/**',
-      'node_modules',
-    ],
+    exclude: ['tests/helpers/**', 'tests/bench/**', 'tests/fixtures/**', 'node_modules'],
     sequence: {
       hooks: 'list',
     },