retry-429-hot-path@fault: bug  # capture-path flush() returns without draining the off-hot-path 429 retry (Retry-After 1s); only the initial attempt reaches the wire — shared python-sdk transport behavior (DEV-1143)
track-attachments@fault: missing_feature  # LangChain callbacks expose no attachment channel; the wrapper capture path cannot ship track_ai attachments, so the driver refuses loudly (exit 4) rather than drop them silently
