The embedding-observation change wrapped every _embed_chunk call in a
span. Cascade-time indexing embeds run outside any request trace, so each
chunk started its OWN root trace — a per-chunk trace explosion (13 orphan
everos.embedding traces per add/flush), detached from session/user and
contrary to the "cascade is not instrumented" decision.
memory_span gains nested_only: open a span only when one is already
active. Embedding uses it, so search/flush embeds still nest under their
recall/extract span, while cascade embeds no-op (no trace) — restoring the
cascade-untraced boundary.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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