Approval marks were emitted under a synthetic 'default' relay session:
the hook payload carried only turn_id/tool_call_id, so the observability
plugin's _session_id() fell back to 'default', parenting approval marks
to a session scope that never closes — and close-time exporters never
shipped them. The audit board's approval tables stayed empty while
approvals were demonstrably firing (staging 2026-08-10).
Bind session_id in set_current_observability_context at both dispatch
sites (model_tools tool dispatch, plugins pre-tool-call approval gate)
and forward it on every approval hook. Explicit session_id in a hook
payload still wins; unbound contexts omit it (legacy behavior).
Victor Kyriazakos