Turn Status

Recovery oracle for a reconnecting chat client: did the last turn finish, is it still streaming, or did its worker die?

Driven off the stream_state lock the worker releases in its finally, so the client never re-runs a live or finished turn (which would duplicate it):

• no lock -> the finally ran -> "completed" (it's in the DB)
• lock + fresh stream -> a worker is streaming -> "in_progress"
• lock + stream silent past DEAD_AFTER_SILENT_SECONDS, no [DONE] -> "dead" (release the stale lock so a reload doesn't re-hang on it)