From 2c0ac74fdd85595c5c29f3db033a0be199087a9f Mon Sep 17 00:00:00 2001
From: "Jonathan D.A. Jewell" <6759885+hyperpolymath@users.noreply.github.com>
Date: Thu, 1 Oct 2026 08:02:31 +0100
Subject: [PATCH 1/2] docs: add Signed commits section to CONTRIBUTING

Owner ruling D218. See docs/SIGNING-POLICY.adoc in hyperpolymath/standards.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WRvDivYwLSeVCJUrfjic3f
---
 .github/CONTRIBUTING.md | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index a6dd3c0..41ed70e 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -121,3 +121,20 @@ type(scope): description
 
 [optional footer: issue reference, e.g. Closes #123]
 ```
+
+### Signed commits
+
+Every commit that reaches the default branch must be signed; a ruleset refuses
+unsigned pushes. Estate policy:
+[SIGNING-POLICY](https://github.com/hyperpolymath/standards/blob/main/docs/SIGNING-POLICY.adoc).
+
+- **People and interactive agents** sign with an SSH key registered on GitHub
+  as a *signing* key (`gpg.format=ssh`, `user.signingkey=<key>.pub`,
+  `commit.gpgsign=true`). The committer email must be verified on that account.
+- **Apps, bots and workflows** never `git push` local commits. They write
+  through the API (`createCommitOnBranch` or the estate `signed-push` action)
+  so that GitHub signs each commit.
+- Merge PRs with **squash**. The ruleset checks every commit on the PR branch,
+  not just the result, so one unsigned commit blocks the merge. Re-create such a
+  branch with signed commits (`git cherry-pick -S`) and open a new PR.
+  Rebase-merge replays commits unsigned and is disabled.

From 04cbecdc8adeaf59d65085381714c17618e62147 Mon Sep 17 00:00:00 2001
From: "coderabbitai[bot]"
 <136622811+coderabbitai[bot]@users.noreply.github.com>
Date: Thu, 1 Oct 2026 14:22:13 +0000
Subject: [PATCH 2/2] docs(contributing): clarify that rebase merging is
 enabled and recommend squash for signed commits

---
 .github/CONTRIBUTING.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index 41ed70e..60141c7 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -137,4 +137,4 @@ unsigned pushes. Estate policy:
 - Merge PRs with **squash**. The ruleset checks every commit on the PR branch,
   not just the result, so one unsigned commit blocks the merge. Re-create such a
   branch with signed commits (`git cherry-pick -S`) and open a new PR.
-  Rebase-merge replays commits unsigned and is disabled.
+  Rebase-merge is enabled in `.github/repo-meta.yml`; use squash for signed commits.