Conflicts resolved:
- CarlConversationHttpTest: keep the integration branch's backoff polling
with its Retry-After assertions, and have that loop use the raw sender so
the 429 contract stays tested; other direct calls keep #46's rate-limit retry.
- SESSION-STATE.md, TODO.md: keep both histories, integration wording first.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>