nx_survey_stats.nx

nx_survey_stats.nx -- the INSIGHTS engine over survey responses (operator 2026-07-10: "we have the survey front end but we dont have any of the statistics or all the capabilities that power meaningful insights"). CONSUMES nx_survey_engine's effective ballots (se_ballots -> vout[i]/lout[i] = ballot record bytes) and question records; turns raw responses into the analytics a real survey product delivers: - descriptive: n/min/max/mean/median/mode/stddev (fixed-point permille, integer isqrt) - CX metrics: NPS (promoters-detractors), top/bottom-box, 95% confidence margin on a proportion - cross-tabulation: r x c contingency of one question by another - significance: chi-square test of independence vs a DATA-DRIVEN critical table (alpha .05), FAIL-CLOSED past df 10 (never a false "significant") -- the adversary's own guard - key drivers: Pearson correlation of every scale question against a chosen outcome, ranked by |r| - segment analysis: mean of a target question within each level of a segment question - trend: before/after split on real ballot timestamps - welfare triage rollup: composes nx_survey's sv_triage/sv_band to count crisis/strained/stable - open text: sovereign tokenized theme frequency (honest: frequency-based, NOT neural topic/sentiment) 100% integer / fixed-point, no floats, no hardware writes. Every stat is hand-KAT'd in the gate and carries an adversarial neg-control (a fabricated significance / correlation must be rejected). license_tier: ORIGINAL