WB Stream removed the room creation API; gen mode for wbstream no
longer works. Remove the wbstream branch from session.Gen, drop the
auto-generate prompt from srv.sh and the entrypoint fallback, and
update docs to instruct users to create rooms manually at stream.wb.ru.
Replace all -carrier references with -auth in settings, manual, fast,
uri, and about. Update architecture diagram and repo structure table
to reflect internal/engine + internal/auth split (replaces internal/provider).
Add pkg/olcrtc section describing the public Go library API.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
