v1.9.0

IDC v25, idc-index 0.13.0 (idc-index-data 25.0.0), REST/MCP API 3.0.0b5. The package bump
carries no API change; the substance of the release is data provenance.

Added

• Provenance (index_tables_guide.md, sql_patterns.md, SKILL.md): who contributed,
  de-identified, and DICOM-converted each part of the archive. Recorded per source, keyed on
  source_DOI — collections_index.sources is a list of structs (unnest it) with a nested
  provenance; analysis_results_index.provenance is a new column. A NULL struct means that
  source is an analysis result, so look it up in the other table — across the pair, coverage is
  complete. NOT_APPLICABLE / UNKNOWN / NOT_DOCUMENTED are values, not nulls
• Four index columns the guides never carried: sop_class_name, transfer_syntax_name,
  PhotometricInterpretation, PixelRepresentation. All four are comma-separated when instances
  in a series disagree (~72 000 series) and the latter two are NULL for SEG/SR/RTSTRUCT, so =
  silently drops mixed-encoding series. sop_class_name, not SOPClassUID, is filterable
• Hugging Face mirror of the Parquet artifacts
  (ImagingDataCommons/idc-index-data,
  public, no token). A fallback only — revision tags are incomplete, so pin via GCS
• Four missing Parquet artifacts: sm_instance_index, version_metadata_index,
  gdc_idc_mapping (the imaging/genomics join), tcia_idc_subset
• TestProvenance, covering the unnest path, the NULL-is-a-pointer rule, and tcga_brca

Changed

• Pinned minimum idc-index 0.12.5 → 0.13.0; documented data version v24 → v25. Older
  installs report v24 and cannot download series added in v25
• Archive totals 176 → 179 collections, ~99 → ~100 TB; mixed-license collections still 39
• API claims 3.0.0b3 → 3.0.0b5; tool inventory, the 19 filterable attributes, and all REST
  limits re-verified unchanged
• BigQuery example idc_v24 → idc_v25. The DICOMweb store stays idc-store-v24 — stores lag a
  release by 1-2 weeks and idc-store-v25 is not populated yet, which dicomweb_guide.md now
  warns about at the point of use

Fixed

• test_snippets.py hardcoded "v24", needing a hand edit every data release. It now reads
  idc-data-version from the frontmatter, so a stale pin fails CI instead of stale guides

What's Changed

• Release 1.9.0: IDC v25, idc-index 0.13.0, and data provenance by @fedorov in #42

Full Changelog: v1.8.3...v1.9.0