`chat_turn` debug steps persist with `attempts: []` even when the
streaming call to Anthropic completes successfully. Fantasy's
Anthropic SSE adapter iterates the response to EOF via
`for stream.Next()` and abandons the body without calling `Close()`,
so `RecordingTransport`'s Close-only recording path never fires and
the attempt is lost. Non-streaming runs (`quickgen`,
`title_generation`) go through `model.Generate(...)` and are
unaffected.
Record on `io.EOF` for `text/event-stream` bodies specifically.
Non-SSE responses stay on the Close-only path so JSON integrity,
content-length validation, and inner-`Close()` error semantics are
preserved. `record()` is already `sync.Once`-guarded, so a later
`Close()` is a no-op for recording.
Thomas Kosiewski