Add the Codex Auto Review model to the provider registry and prefer
Codex when resolving unprefixed `codex-auto-review` and `gpt-5.5`
requests.
Broaden provider icon mappings and bundled PNG assets so more providers
render correctly in the shared UI. Also tighten chatCore stream cleanup
behavior so streaming responses return immediately while semaphore slots
and model locks are released on completion or failure, with tests and
artifact policy coverage updated accordingly.