v7.40.0

Paired engine: engine-service-v0.1.113, unchanged from 7.39.0 (no
service/ change in this release). REQUIRED_ENGINE_VERSION is
(0, 1, 113).

RDR fix check: replicate critics and consensus (nexus-dxksa)

• Four runs of the identical fix-check brief on the identical commit
  (RDR-205 at fb60c3f) raised eleven distinct findings, one in all four
  runs and five in exactly one, so about half of any single run's FAIL
  rows did not reproduce, and "any FAIL: fix, re-run" resampled on every
  re-run (RDR-204: ten gate rounds; RDR-205: five rounds and twelve fix
  checks in two days). The fix check is now three independent dispatches
  of one brief; a defect counts only when at least two raise it at the
  same site, with the majority class; every row carries a Class
  (BLOCKS-PLANNING, DISCOVER-AT-IMPLEMENTATION, OBSERVATION) and only a
  counted BLOCKS-PLANNING defect fails; a failed check is fixed once and
  checked once more, then its counted defects are residuals for accept.
  One sentence in nexus.commands.rdr, carried verbatim by the printed
  brief, the fix rules, the accept preamble, and the rdr-gate, rdr-fix
  and rdr-accept skills and command mirrors, pinned by equality in
  tests/test_plugin_structure.py. Tested before shipping: the six
  consensus findings were fixed and three fresh replicates under the new
  brief converged on the same document in one round.

RDR tooling (carried from develop after 7.39.0)

• Layer 0 retires a finding confirmed closed in the last two rounds; a
  gate round appends one Revision History line and the findings live in
  the T2 records; the gate record's prior chain names each round's own
  critique id; one disposition line at accept (nexus-yjf5l.11, .12, .13).