Added io.paraview_series to post.pipeline: PICurv writes a .pvd ParaView collection indexing existing VTK frames by checkpoint physical time after successful field postprocessing. scope: lineage follows the run manifest's restart ancestry, clips each parent at its child's fork step, and lets the child own a duplicate fork frame; scope: run indexes only the current run. Indexing is a presentation product over already-produced VTK output and does not change computational recipe identity. picurv run --post-process --continue can be repeated while a solver is active, appending newly available frames and atomically refreshing the collection each time.