Main's dependency-graph guard ceilings components->features imports at 33
and this PR's RenderErrorBoundary -> features/diagnostics/render-error-log
was a new upward edge (34) — the one P1 in CI. The log is generic session
infrastructure, not a feature: it lives in lib/ now, so the merge against
main nets zero new upward edges, and the Diagnostics screen keeps reading
it downward like any other feature.