chore: import upstream snapshot with attribution

docs/management/runs/retrieve-trace.mdx

@@ -0,0 +1,8 @@
+---
+title: "Retrieve run trace"
+openapi: "v3-openapi GET /api/v1/runs/{runId}/trace"
+---
+
+Returns the OpenTelemetry trace subtree for the run you request. The response `trace.rootSpan` is that run's span — not necessarily the trace-wide root — with its descendant spans nested under `children`.
+
+For a child or nested run inside a large trace, this endpoint scopes the tree to that run so you still get a useful subtree even when the full trace has more spans than the platform can return in one response.