fn agent_calls_branch(
traces: &[CallsSource],
window: &GraphQueryWindow,
) -> Result<Option<DataFrame>>Expand description
The parent_agent calls agent derivation over trace tables declaring an
agent entity: pair each span with its child span (no span-kind filter —
agent spans are typically INTERNAL) across all agent-declaring tables, keep
pairs whose agent identities differ, and aggregate RED metrics per 60s
window. Anchored like the service derivation on the caller: the parent side
is bounded to the source window and stamps observed_at, the child side
widens by the time-proximity allowance and supplies status/duration.