This release makes argument imports more reliable and easier to troubleshoot.

• Imports always reach a final state. Previously, if a step of an import failed in a certain way, the import could get stuck indefinitely with no explanation. Imports now always settle — either succeeding, or failing with a recorded reason — and a background safety net recovers any that would otherwise have stalled.
• See why a step failed. When an import step fails, the reason now appears in the per-step detail on the import's status page, color-coded by severity, instead of showing an empty list.
• No more silently-doomed imports. The server now checks that it can actually receive completion callbacks before starting an OpenAI-backed import. If it can't, the import is declined right away with a clear message rather than appearing to start and then hanging forever.