From 5b9c142d1b841a02d3a7e7f8aef43c040117476f Mon Sep 17 00:00:00 2001
From: Nils Lehnen <30603423+iderex@users.noreply.github.com>
Date: Sun, 23 Aug 2026 15:19:22 +0200
Subject: [PATCH] Call the shared hygiene check beside this board's own gate

The rules every board in this fleet shares now have one implementation in
`iderex/wache`, and this board was not calling it. It carried its own copy
instead, as every other board did, which is the divergence argued in
iderex/operations#1556: a change to a shared rule cost one edit per board and
failed differently on each.

The call runs beside `.github/pr-hygiene/hygiene.sh` and replaces nothing.
Neither that script nor `.github/workflows/pr-hygiene.yml` is touched. What the
shared check adds here is a placeholder title and a closing keyword buried in a
paragraph, neither of which this board reads today. What it has no equivalent
for is the scope comparison, the qualifier aware reading of a reference, the
rule that a body names an issue rather than closing one, and this board's own
sense of an empty body, so the local rules all stay.

The subject rule is switched off. The shared check wants the issue number in the
commit subject in square brackets; of the 52 authored subjects the first page of
`main` returns, none carries that shape and the twelve most recent carry no
reference in the subject at all. On says every pull request here reddens from
day one. Off says the board does not meet that rule yet, which somebody can act
on. Not calling the check would say nothing.

The failure this prevents on the way in is a cancelled check. The called
workflow declares the concurrency group `pr-hygiene-<pull request number>` with
cancel-in-progress, and `.github/workflows/pr-hygiene.yml` here declares the
same string. On `iderex/bremsweg`, whose local group is written identically and
whose caller declares none, the local run was cancelled on the very commit that
added the shared call. This file declares its own group, so the two runs cannot
sweep each other up.

Refs #178

Signed-off-by: Nils Lehnen <30603423+iderex@users.noreply.github.com>
---
 .github/workflows/shared-hygiene.yml | 74 ++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 .github/workflows/shared-hygiene.yml

diff --git a/.github/workflows/shared-hygiene.yml b/.github/workflows/shared-hygiene.yml
new file mode 100644
index 0000000..6fa1bb0
--- /dev/null
+++ b/.github/workflows/shared-hygiene.yml
@@ -0,0 +1,74 @@
+# The shared half of the pull request hygiene rules, called rather than copied
+# (#178).
+#
+# WHY THIS FILE EXISTS. `iderex/wache` holds one implementation of the rules
+# every board in this fleet shares, and the argument for calling it instead of
+# growing another copy is iderex/operations#1556: nineteen boards carried
+# nineteen implementations of the same three or four rules, in four languages,
+# no two alike, so a two line change to a shared rule cost nineteen edits and
+# failed in nineteen different ways.
+#
+# WHAT IT ADDS HERE. Two things this board does not read today: a placeholder
+# title such as `wip`, and a closing keyword sitting inside a paragraph instead
+# of on a line of its own.
+#
+# WHAT IT DOES NOT REPLACE. Nothing beside it changes. Four rules in
+# .github/pr-hygiene/hygiene.sh have no equivalent in the shared check at all:
+# the comparison of changed paths against the `Scope:` line of every issue the
+# body names, the qualifier aware reading that lets `owner/repo#N` be pasted as
+# evidence without becoming a question about this board, the rule that a body
+# names an issue rather than closing one, and the emptiness rule as this board
+# means it, where the template skeleton with a number filled in is refused. A
+# local rule goes only once the shared check is shown to cover it, one rule at a
+# time, in its own change. Standardising by deleting coverage would be worse
+# than the duplication.
+#
+# THE SUBJECT RULE IS OFF. The shared check wants the issue in the commit
+# subject in square brackets. Of the 52 authored subjects the first page of this
+# board's default branch returns, none carries that shape and the twelve most
+# recent carry no reference in the subject at all, because this board puts the
+# reference in the body on purpose and its own check reads the body. Switching
+# this one rule off says the board does not meet that rule yet, which is a
+# statement somebody can act on. Calling the check with the rule on would refuse
+# every pull request here on day one. Not calling the check at all would say
+# nothing.
+#
+# PINNED BY HASH, NOT BY BRANCH. A moving reference would let the called
+# repository change what executes here without anybody reviewing the change, and
+# zizmor on this board refuses an unpinned reference anyway. The hash below is
+# the one every other caller in the fleet carries, and the file it resolves to is
+# byte for byte the file the newer tag carries, so this board executes the same
+# bytes as the rest.
+#
+# THIS FILE DECLARES ITS OWN CONCURRENCY GROUP AND THAT IS NOT DECORATION. The
+# called workflow declares `pr-hygiene-<pull request number>` with
+# `cancel-in-progress`, and that is the same string
+# .github/workflows/pr-hygiene.yml on this board already uses. A caller that
+# declares no group of its own is left in that group, and then the two runs
+# cancel each other: on another board carrying the identical local group, the
+# local run was cancelled on the very commit that added the shared call, and the
+# grey check has stood there since. The group below cannot collide with it.
+name: Shared hygiene
+
+on:
+  pull_request:
+
+# Deny everything at the workflow level and grant the called job the one scope
+# it needs, which is the shape every other workflow in this directory uses.
+permissions: {}
+
+# Cancel a superseded run on the same pull request. Reading an older body tells
+# nobody anything, and the name is this file's own so that the local hygiene run
+# is not swept up with it.
+concurrency:
+  group: shared-hygiene-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  hygiene:
+    name: Shared PR hygiene
+    permissions:
+      contents: read
+    uses: iderex/wache/.github/workflows/pr-hygiene.yml@9b311243c2d0d0ced7feb957a20bc178acce6a5d # v1.0.0
+    with:
+      subject_names_issue: false