index/index.js:1070:Mw seals a commit's parents with i < 16, silently dropping
the 17th+ parent of an octopus merge. The real constraint — CPAR's ord
lives in a 4-bit vnib (INDEXES.mkd) — is stated nowhere at the site: no named
constant, no ticket, and INDEXES.mkd's CPAR entry says "one row per parent"
with no cap. A dropped parent falsifies the DAG lite log walks. Found in
the 2026-08-21 review.
Name the constant, document the cap where CPAR is specified, and either warn at seal time or extend past 16 the way REV-PARS rides a second row.