Pre-call extraction only read top-level Converse text blocks, so blocked
content placed under toolResult.content[].text was forwarded to Bedrock
without the key/team guardrail seeing it. Extraction now walks nested tool
result text and write-back mutates the owning block in place.
Post-call buffering for passthrough used _has_post_call_guardrails, which
excludes event_hook=None guardrails. Those guardrails run at post_call, so
their output processing was skipped and the raw upstream body was returned.
Add a passthrough-specific predicate that counts them.