[kieronlanning]

Why

purview-dev/engineering-playbook was reorganised (PRs #13/#14, main at 6b68c6a) and the catalogue
entry no longer described it:

• docs/wiki/index.md and mkdocs.yml were deleted. The wiki is now plain Markdown: Home.md is
  the hub, _Sidebar.md is the whole navigation, and the repository carries no site configuration.
• A new page, docs/wiki/foundations/Dependency-Versions.md, is linked from Home.md and listed in
  _Sidebar.md under "Repository foundations".
• The playbook now publishes eight skills (the eighth is purview-component-compatibility).
• The wiki no longer states package versions; it renders registry badges instead.

This PR also applies the same rule to this repository: its own dead mkdocs.yml is gone, and the build
now reports (never fails on) any project repository that still ships one.

What changed

src/src/data/projects/engineering-playbook.yml

• docs.exclude is now [_Sidebar.md] only — index.md no longer exists, and nothing else needs
  excluding. docs.source: github-path, docs.path: docs/wiki and docs.rootPage: Home.md all still
  resolve (Home.md is itself a conventional root page, so rootPage restates the default).
• The first use case no longer pins "Purview.BuildSdk": "1.0.4". It uses the playbook's own
  placeholder convention ("LATEST", as in Getting-Started.md), because the page it advertises now
  deliberately states no version at all — a real number here would rot and re-introduce the
  contradiction.
• No skill count is hand-maintained anywhere: ProjectCard.astro and projects/[project].astro derive
  it from listMirroredSkills(), i.e. from the mirror just data-sync discovers at the project's
  documentation ref. The new skill appears with no catalogue change; the sync mirrors eight skills for
  the playbook (purview-architecture, -architecture-testing, -component-compatibility,
  -engineering-principles, -org-harvest, -persistence, -telemetry, -testing-conventions).

Aggregation, proved end to end

just data-sync reports docs engineering-playbook: 22 pages (Docs synced: 16 projects, 269 pages).
The page list is exactly _Sidebar.md's order, with the new page in its sidebar position: -1 index
(from Home.md), 1 getting-started, 2 engineering-principles, 3 foundations/repository-shape,
4 foundations/project-responsibilities, 5 foundations/architecture-as-tests,
6 foundations/verification-model, 7 foundations/documentation-convention,
8 foundations/dependency-versions, 9 data/contracts-and-data-exchange, …, 21 examples/worked-examples.

No page is emitted for the deleted index.md; the only index slug is the landing page, aliased from
Home.md. The built site serves the new page (HTTP 200, title "Dependency Versions | Purview Dev"):

/docs/engineering-playbook/foundations/dependency-versions/

Note on that URL: a page's slug is its path from the docs root (ADR 0011), so a page in foundations/
publishes at /docs/<id>/foundations/<page>/, and the flat
/docs/engineering-playbook/dependency-versions/ does not exist (404). That is the documented rule —
the playbook's own Home.md states the same contract — so I neither flattened the slug nor invented a
redirect for a URL that never existed.

Badges survive the aggregator

All eleven badge images render as their absolute URLs — no raw.githubusercontent.com rewrite and no
imageBase prefix: https://img.shields.io/nuget/v/Purview.BuildSdk …
https://img.shields.io/npm/v/@purview-dev/astroc4.

rewriteDocMarkdown already returned absolute (https://///) targets untouched, so no code fix was
needed; the behaviour is now pinned by tests so a future image-rewrite change cannot silently break a
page that shows a version as a badge.

Dead references and the stale exclude

• No reference to a playbook index page remains. The guidance that assumed "every wiki ships an
  index.md, exclude it" is corrected in docs-aggregation-rules, add-catalogue-project,
  audit-catalogue-projects, project-manifest-reference and the catalogue auditor checklist, which
  now say: the wiki is plain Markdown, Home.md is the hub, _Sidebar.md drives the order and the
  navigation, and the catalogue entry alone decides what is published.
• An exclude naming a file that no longer exists is confirmed to be a no-op — isExcluded filters the
  files the repository ships and nothing validates the patterns against a file list, so a stale pattern
  neither warns nor fails, and no message needed tightening. A test pins it.
• No other project entry is touched.

Site configuration files: removed here, reported elsewhere

• mkdocs.yml is deleted from this repository. It configured a Material/TechDocs site for docs/
  that nothing builds — the site is Astro + Starlight, and no workflow, recipe or script reads it.

• just data-sync now reports, but never fails on, a project repository that still ships one
  (findLegacySiteConfig in src/lib/docs/aggregate.ts, called on the tree the aggregation already
  fetches, deduped per project, exported and unit-tested). The live sync inside this PR's own
  just validate printed exactly one line for each of the eight that still do:

  docs architests: mkdocs.yml is a repository site configuration and the portal ignores it — the
  catalogue entry alone decides what is published, so the repository can drop the file.
  … also aspire-resourcekit, build, build-sdk, containers, event-sourcing,
    sourcegenerator-framework, zodsharp
  

  It is an advisory rather than a gate, so each of those repositories can delete the file in its own
  pull request; stripMkdocsMarkup keeps tolerating the Material markup such a file stands for until
  then (containers is the live example), and the line disappears once the file is gone.

Tests (src/tests/unit/docs.test.ts)

• link rewriting > keeps an absolute badge image beside a relative one and
  … keeps a scoped npm badge image unchanged.
• docs exclude matching > a pattern for a file the repository no longer ships is a no-op — root
  selection for the playbook's shape (Home.md hub, _Sidebar.md excluded, index.md matching nothing).
• legacy site configuration > … — detection at any depth, case-insensitively, absent from a plain
  Markdown tree, and no false positive from mkdocs.yml.bak/mkdocs-notes.md.

Validation

• just validate passed as the pre-push hook on both pushes (no --no-verify, no admin merge, no
  force-push): format → lint → typecheck → 350 unit tests → asset/catalogue checks → build (live data
  sync, 269 pages) → discovery → link crawl → generated-output check → built-output tests.
• bun run ci:build locally: astro check 0 errors / 0 warnings / 0 hints, catalogue check 17
  projects, 294 pages built, all checks green, dist tests 42 pass / 2 skip / 0 fail.
• just test 350 pass / 0 fail; just format-check and just lint clean.

The remaining build warnings are pre-existing and come from upstream content, untouched here:
aspirec4's ```likec4 fence in a .md page, its gitignore code fence with no highlighter,
the Vite chunk-size advisory, and LikeC4's "no likec4 documents found in workspace".