Migrate LangSmith → Arize AX

Move LangSmith data into Arize AX. Historical traces are in scope — export LangSmith runs and ingest them into AX via OTLP with explicit attribute mapping. Also migrate datasets and optionally cut over live traffic.

SPACE — --space / ARIZE_SPACE accept a space name or base64 ID. Prefer the user-provided name; do not paginate ax spaces list just to look it up.

When to use

• Migrate / import LangSmith → Arize AX
• Move LangSmith runs/traces into an AX project
• Import LangSmith datasets into AX

Core principles