Add `.flatten_event(true)` to tracing-subscriber JSON layers so event
fields (message, index, duration_ms, node_count, estimated_hits,
degraded) appear at the top level of each JSON log line, matching the
flat schema specified in plan §10.
Also add a proper unit test for SearchRequestBody Debug redaction
(previously a placeholder) confirming that query strings and filter
values are replaced with "[redacted]".
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
e092164e70