Add atlas annotation rule for vessel nodes parquet

[Copilot]

Vessel nodes lacked atlas region labels, making it impossible to aggregate vessel metrics by brain region. This adds a Snakemake rule and script to annotate vessel node parquets with atlas ROI labels using ZarrNiiAtlas.label_region_properties.

Changes

• vessels.smk — new rule map_atlas_to_vessel_nodes

  • Inputs: nodes.parquet (from vessel_graph_to_nodes_edges), subject-space atlas dseg (datatype="parc", from_="{template}"), and label TSV
  • Outputs: atlas-annotated nodes.parquet and nodecounts.tsv, with seg and from_ wildcards appended to the filename — mirroring the wildcard strategy of map_regionprops_to_atlas_rois
  • Uses physical coordinate columns ["x", "y", "z"] from the nodes schema

• scripts/map_atlas_to_vessel_nodes.py — new script following the same pattern as map_atlas_to_regionprops.py:

  nodes = pd.read_parquet(snakemake.input.nodes_parquet).to_dict(orient="list")
  atlas = ZarrNiiAtlas.from_files(snakemake.input.dseg, snakemake.input.label_tsv)
  df_nodes, df_counts = atlas.label_region_properties(
      nodes,
      coord_column_names=snakemake.params.coord_column_names,
      include_names=True,
  )
  df_nodes.to_parquet(snakemake.output.nodes_parquet, index=False)
  df_counts.to_csv(snakemake.output.counts_tsv, sep="\t", index=False)