nx_kanon.nx

nx_kanon.nx -- LIB (PURE math, no I/O): the k-anonymity FLOOR primitive. Load-bearing privacy foundation under ADS-018 conversion measurement AND W-AN-CHARTER-002 / W-CLI-C6 anti-harm analytics (DRY rule 15 -- ONE k-anon home). Non-ads named on purpose so the analytics charter can ride it without importing ad code. THE INVARIANT: an aggregate count is RELEASED only when it cannot single out a person -- i.e. count == 0 (reveals nobody) or count >= K. A count in [1, K-1] is SUPPRESSED. After release, NO released cell carries a count in [1, K-1] (cells_below_k == 0). PURE: K arrives as a parameter; the SOURCE of K is config in the sovereign store (the ad engine reads it via nx_ad_store -> adcfg:kanon_k), never a TSV/conf flat file. Keeping this lib pure means any consumer (ads, analytics) supplies its own K source. license_tier: ORIGINAL