fix: resolve review blockers for comments redesign

- Fix context key mismatch in _render_htmx_success ('reply' vs 'comment')
- Update OOB swap selector to match new sibling relationship for replies container
- Update HTMX reply tests to verify correct OOB selector and content rendering
- Fix variable naming in _reply.html to match parent context

apps/comments/tests/test_v2.py

@@ -132,12 +132,13 @@ def test_htmx_reply_returns_oob_reply_when_approved(client, _article, approved_c
         )
     content = resp.content.decode()
     assert resp.status_code == 200
-    # OOB targets the parent's replies-container
-    assert f"#comment-{approved_comment.id}" in content
-    assert "hx-swap-oob" in content
-    # Reply uses compact markup (no nested reply form)
-    assert "Reply posted!" in content
+    # OOB targets the sibling .replies-container of the parent comment article
+    assert f'hx-swap-oob="beforeend:#comment-{approved_comment.id} ~ .replies-container"' in content
+    # Verify content is rendered (not empty due to context mismatch)
+    assert "Replier" in content
+    assert "Nice reply" in content
     reply = Comment.objects.exclude(pk=approved_comment.pk).get()
+    assert f"comment-{reply.id}" in content
     assert reply.parent_id == approved_comment.id
     assert reply.is_approved is True