CRISPRme v2.3.1

Fixed

• Dict-less download --what index is now self-sufficient. A standalone
  download --what index for a merged variant index (e.g.
  NRG_3_hg38-dictless+hg38_1000G_HGDP) now fetches the per-dataset samplesID
  lists it needs before synthesizing the combined <vcf>.samplesID.txt, so it no
  longer requires a prior download --what all/--what samples. No-op when those
  files are already present (the --what all → --what index path is unchanged).
• Restored the unit-tests CI gate. A colon in a workflow step name
  ((#172: fakechrom match)) made GitHub Actions reject unit-tests.yml at startup
  (a 0 s "workflow file issue"), so the unit-tests job had silently not run since the
  v2.3.0 merge (the tests themselves pass locally). Quoting the name fixes the parse;
  the full 22-step unit suite runs in CI again.