Run a PSI intersection

confium privacy psi \
  --set-a customers.txt \
  --set-b watchlist.txt \
  --cardinality-only

• Inputs are one entry per line; pre-hash them upstream if entries are sensitive in your environment.
• --cardinality-only prints just the count — the default minimum when you only need “how much overlap”.
• --salt overrides the default salt source (/dev/urandom) for reproducible test runs; never fix a salt in production.