fix(js): deepFreeze recurses below already-frozen parents

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

js/test/m01-util.test.js

@@ -45,3 +45,13 @@ test('m01 deepFreeze returns the same object it was given', () => {
   const o = {}
   assert.equal(deepFreeze(o), o)
 })
+test('m01 deepFreeze reaches unfrozen children of an already-frozen parent', () => {
+  const o = deepFreeze({ a: Object.freeze({ b: { c: 1 } }) })
+  assert.ok(Object.isFrozen(o.a.b))
+})
+test('m01 deepFreeze handles cyclic objects', () => {
+  const o = { child: {} }
+  o.child.parent = o
+  deepFreeze(o)
+  assert.ok(Object.isFrozen(o) && Object.isFrozen(o.child))
+})