writing.md names a check-writing.sh that does not exist, so the em-dash rule is unenforced

[rusholme]

What the purpose requires

The writing design states mechanical style rules and says they are enforced
by a pattern scan that runs in the pull-request checks. For that statement to
be true, the scan has to exist and has to run. A rule the site describes as
blocking should block.

What exists today

system/writing.md line 238 names the scan as scripts/check-writing.sh and
describes it as running beside check-public-safety.sh in the pull-request
checks. That file does not exist. scripts/ contains only acceptance.sh and
check-public-safety.sh.

The gap was found by walking into it. Commit 5258ab5 (2026-09-12, "Make the
em dash a blocking check") established that every page on the site is free of
em dashes and that the scan blocks on one rather than warning. On 2026-09-13 a
new page, system/glossary.md, was written and committed carrying 22 em
dashes, with 5 more added to repositories.md and 1 to code-standards.md.
Nothing objected: check-public-safety.sh returned OK, the Sphinx build
succeeded, and scripts/acceptance.sh passed every check. The violation was
caught by a human-directed review reading the commit history, which is exactly
the labour the scan exists to replace.

So the rule is real and ratified, the pages comply with it by hand, and the
enforcement the design claims is live is not wired up. A rule that depends on
each author knowing it is a convention, not a check.

The trigger that reopens this

This is open now. It closes when scripts/check-writing.sh exists, runs in
the same place check-public-safety.sh runs, and fails on an em dash in a
tracked page. Until then, writing.md line 238 describes machinery the
repository does not have, and either the script or that sentence needs to
change.