docs(adr): ADR-0131 dated notes for the 18.x line — release scope, D1 as ruled, the D9 lean-embedding exception and its boundaries

D1 takes the wording ruled on #25134 (6328195425, letter A), with the
accepted text quoted in its Amended note. Dated notes record the 18.0.0
release scope (6291577585, 6323222024), D1 at CREATE TABLE (#24940),
the organization delete under ruling B (#25016), D2's deploymentWide
marker (#24828), D5's last-admin guard (#25141), D7's attribution NULL
arm (#24825), D8's implemented gate (#24880, #25140) and its one
uncertified residue (6325596117), and D9's lean-embedding exception
under ruling A on #25133 (6328987873). #25133's fix and #25134's
advisory are in flight and cited by card.

Refs #24897

Co-authored-by: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UQCyrGmMy6kwav9XCzAuQ9

Author: claude