Plan · CHG-2026-014903 · Agentic SDLC

change_id: CHG-2026-014903
risk_class: R3
autonomy_tier: A2
controls: ['CHG-04', 'TRC-01', 'SOD-01', 'TPR-05']
data_classification: public
originator: olaf@freundcloud.com
agent_identity: svc-agent-platform
model_route: gateway/tier-frontier
supersedes: None

Approach

Correct the untrue claims before adding anything, so the site is generated from a tree that already says true things. Then the agent invocation, which is a behaviour change to the workflows and wants its own verification. The site last, because it is the only part that cannot break a gate.

The site is generated rather than authored: site/build_pages.py reads the chain through scripts/artifacts.py, the same parser the gates use. A hand-copied playbook would be a second source of truth, and the first thing this repository argues against is a document that describes a reality it is not connected to.

Files

site/**
.github/workflows/pages.yml
.github/workflows/02-design.yml
.github/workflows/03-gates.yml
.github/workflows/06-operate.yml
.github/actions/assign-copilot/**
scripts/tests/test_readme_claims.py
CODEOWNERS
.gitignore

Sequence

Repoint CODEOWNERS at @olafkfreund. → verify: check_codeowners.py passes against GitHub’s validator, not the offline fallback.
Correct the README’s headline scores and add test_readme_claims.py. → verify: make test green, and the test fails if a number is edited back.
Pass GH_TOKEN to the CODEOWNERS gate; guard the segregation-of-duties job to pull_request. → verify: evidence record reports validator: github.
Add .github/actions/assign-copilot and wire it into Stages 2 and 6. → verify: the step re-reads assignees and reports honestly on both the available and unavailable paths.
Add site/ — config, layouts, Gruvbox stylesheet, four authored pages. → verify: Jekyll builds with no external request.
Add site/build_pages.py and pages.yml. → verify: one page per artifact, header rendered rather than consumed; the deployed URL serves the site.
Re-run everything. → verify: make build test lint gates, make eval, make substitution at 12/12, make negative at 12 refused.

Risks

Risk	Likelihood	Mitigation
The site drifts from the repository it describes	high — the default fate of any generated documentation	The playbook and the chain are generated at build time from the files on disk; generated files are git-ignored so no stale copy can be committed
An artifact’s §6.2 header is silently eaten as Jekyll front matter	high, and invisible when it happens	`build_pages.py` re-emits the header as a fenced YAML block and writes its own front matter
The agent assignment appears to succeed while doing nothing	medium — this is exactly how the previous `@copilot` mention failed	The action re-reads the assignees after the mutation and warns when the assignment did not land
A public site makes demo evidence look like real audit records	low, high impact	Labelled in the README, the site footer and the index page; the payload is a synthetic service
Branch protection makes the repository unusable for a single maintainer	medium	Admins are not forced through the ruleset; segregation of duties remains enforced structurally by CODEOWNERS and the production environment

Rejected

Building Pages from docs/ or the repository root. Either publishes files that are not pages, or requires exempting files from the plan-conformance gate to keep it quiet. Both trade a real control for a smaller diff.
A Jekyll theme gem. A Gemfile and a bundler lock for one stylesheet, in a repository that argues about dependency surface.
Copying the playbook text into site/. Faster, and wrong for the same reason the repository exists.
Leaving docs/org-prerequisites.md claiming Copilot is unavailable. It was true of the previous organisation and is false here. A stale prerequisite is a claim.

Tests

scripts/tests/test_readme_claims.py — the headline scores, against the tree
make negative — unchanged, still twelve refusals
python site/build_pages.py — idempotent, page count matches the parsed chain

Rollback

Disable the Pages deployment and revert the commit. The site is generated, so nothing downstream holds state. The workflow changes are additive: reverting them returns the agent steps to a mention, which is where they were.