feat: archived-repo pattern + reusable-workflows archival groundwork

[devantler]

🤖 Generated by the Daily AI Engineer

Why

reusable-workflows was merged into actions months ago but can't be archived: its settings CRs would error forever against a read-only repo, and no declarative pattern for archived repos existed. This blocks actions#425's final acceptance criterion and the monorepo docs repoint behind it.

What

Adds an archived-repositories/ pattern (repos managed outside the org-wide merge-policy patch) and Observe-adopts reusable-workflows into it; removes the repo's three active management CRs (none can delete live GitHub state). Safe to merge now — this phase only reads.

Operational note: the actual archived: true flip is a small follow-up PR, gated on the org required-workflow rulesets repointing off the repo first (#87 — one-click commands prepared there).

Part of devantler-tech/actions#425.

[coderabbitai]

📝 Walkthrough

Walkthrough

Adds an archived-repositories/ Kustomize directory containing an observe-only Crossplane Repository for reusable-workflows and documents its two-phase archival lifecycle. The root deployment now includes this directory. Active labels, repository permissions, and maintainer team-repository resources for reusable-workflows are removed from their respective Kustomizations.

Possibly related issues

• fix: repoint the six org required-workflow rulesets off reusable-workflows (blocks its archival) #87 — Concerns the archival of reusable-workflows and related organization configuration needed to complete that archival.

Possibly related PRs

• devantler-tech/.github#67 — Introduced the repository-permissions configuration that this PR removes while adding the archived observe-only repository manifest.
• devantler-tech/.github#79 — Modifies the same labels Kustomize wiring while changing repository-specific label resources.

🚥 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.
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 summarizes the new archived-repo pattern and the reusable-workflows archival groundwork.
Description check	✅ Passed	The description matches the changeset and accurately explains the archived-repositories pattern and observe-only archival phase.

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