docs: add Signed commits section to CONTRIBUTING

[hyperpolymath]

Adds a Signed commits section to this repo's CONTRIBUTING, per owner ruling D218. The estate policy is docs/SIGNING-POLICY.adoc in hyperpolymath/standards.

This repo's default branch is covered by the zero-bypass Require-Signed-Commits ruleset, and rebase-merge is off. The section tells contributors what that requires:

• People and interactive agents sign with an SSH signing key.
• Apps, bots and workflows write through the API, so GitHub signs their commits.
• PRs are merged with squash.

If the file already had its own signing section, that section is replaced in place instead of adding a second one. Lines elsewhere that told people to sign with GPG are changed to match the policy (SSH for people).

This is a docs-only change. The commit was created through createCommitOnBranch, so GitHub signs it.

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🔇 Additional comments (1)

.github/CONTRIBUTING.md (1)

137-138: LGTM!

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📝 Summary

Summary by CodeRabbit

• Documentation
  • Updated contribution guidance to require signed commits on the default branch. People and interactive agents must use a registered SSH signing key and verified committer email; apps, bots and workflows must create commits through the documented API or action.
  • Clarified that pull requests must be squash-merged and rebase merges are disabled. Unsigned commits block merging; replace them with signed commits and update the existing pull request, opening a new one only if permissions or project policy require it.

Walkthrough

The contribution guide sets signed-commit requirements for people, interactive agents, apps, bots and workflows. It also specifies squash merging and how to handle unsigned pull request commits.

Changes

Contribution policy

Layer / File(s)

Summary

Commit signing and merge guidance .github/CONTRIBUTING.md

The guide requires signed commits and gives separate procedures for people and interactive agents, apps, bots and workflows. It requires squash merges. If a pull request branch contains an unsigned commit, the guide instructs contributors to recreate the branch with signed commits and update the existing pull request, except when permissions or project policy require a new one. It also states that rebase-merge is disabled.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~4 minutes

Change: Other

Merge Risk: ⚪ Minimal · up to da7b3

The guide’s signing and PR-recovery instructions have no supported policy conflict; no actionable merge-blocking risk remains.

Architecture Summary

Architecture risk: 🔵 Low · up to 8c871

The changed surface does not map to a changed system, dependency edge, entrypoint, or external dependency.

Changed systems: None identified.

Architecture concerns
No architecture-level concerns identified.

Review details

Before / after behavior

• observed — Modified behavior in .github/CONTRIBUTING.md: Adds signing requirements and separate procedures for human/interactive-agent commits and app, bot and workflow commits. Specifies squash merging, requires unsigned PR branches to be recreated with signed commits in a new PR, and states that rebase-merge is disabled.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the main change: adding a signed-commits section to CONTRIBUTING documentation.
Description check	✅ Passed	The description explains the purpose, policy context, key documentation changes, scope, and commit method. It does not reproduce the repository checklist, but the required information is otherwise mos…

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Actionable comments posted: 1

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Inline comments:
Review comments at @.github/CONTRIBUTING.md:
- Around line 135-137: Update the signed-commit guidance in the squash-merge
paragraph to allow contributors to replace commits on the existing PR when
branch permissions permit; advise opening a new PR only when permissions or
project policy require it.

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📥 Commits

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• .github/CONTRIBUTING.md

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⏰ Context from checks skipped due to timeout. (22)

• GitHub Check: semgrep-cloud-platform/scan
• GitHub Check: scan / gitleaks
• GitHub Check: scan / shell-secrets
• GitHub Check: governance / Well-Known (RFC 9116 + RSR)
• GitHub Check: governance / Licence consistency
• GitHub Check: governance / Security policy checks
• GitHub Check: governance / Check Workflow Staleness
• GitHub Check: governance / Language / package anti-pattern policy
• GitHub Check: governance / Guix primary / Nix fallback policy
• GitHub Check: governance / Workflow security linter
• GitHub Check: governance / Trusted-base reduction policy
• GitHub Check: scan / rust-secrets
• GitHub Check: governance / Code quality + docs
• GitHub Check: rust-ci / Detect Cargo.toml
• GitHub Check: hypatia / Hypatia Neurosymbolic Analysis
• GitHub Check: Hypatia neurosymbolic scan
• GitHub Check: Empty-linter (invisible characters)
• GitHub Check: Validate eclexiaiser manifest
• GitHub Check: Validate K9 contracts
• GitHub Check: Validate DEED manifests
• GitHub Check: panic-attack assail
• GitHub Check: Groove manifest check

🔇 Additional comments (1)

.github/CONTRIBUTING.md (1)

123-138: LGTM!