One CI step beside the self-ref pin, and test/vendored.test.sh covering
both directions: the manifest -> tree scan (missing, symlink, directory,
empty, ../ escape, absolute, untracked) and the closed-world root rule
(neither list, vendored, exempted, prose is not an input, no recursion
below the root), plus the real tree unmodified and the RELEASES.md
regression both ways.
The one-off `grep -Fx RELEASES.md` row at test/docs-sync.test.sh is
deleted (#251 D4): two spellings of "the manifest is right" is the drift
the manifest exists to prevent. Its intent is now a guard case, which the
next doctrine file inherits for free.
Refs #251
5677710b2c