AML Lookback Disposition Rollup

Closes the loop art-470 (lookback-completeness-reconciler) and art-471 (disposition-sampling-frame) leave open. Art-470 reconciles that the RE-SCREENING extract was complete; art-471 builds a deterministic sample of the resulting dispositions for independent review; neither checks that a disposition was actually recorded for every sampled item, that a filed or no-SAR determination carries a rationale, or that the sample frame's declared population size still reconciles to the completeness population. This node rolls those three axes up: disposition-coverage against the sample frame's own declared size, disposition-rationale-presence on every filed/no-SAR determination, and a population-to-sample tie-out between art-470's and art-471's declared population sizes. Emits a closed §27.4 gate-policy value: full coverage with rationale present on every filed/no-SAR item yields auto_pass; any missing disposition evaluated as of a caller-declared date on or after the lookback's declared close date yields escalate; a population tie-out failure or an explicit caller-declared sampling-frame discrepancy yields hold; a disposition present without its required rationale yields review_required. Customer id and alert id cross this kernel already salted -- callers supply a sha256-salted@1 commitment string, never the plaintext identifier -- and the kernel never sees, requests, or computes over the plaintext. Deterministic rollup arithmetic only. Zero network, zero PII.

Tool URL: https://ainumbers.co/chaingraph/art-534-aml-lookback-disposition-rollup.html