Publish the repository wiki through GitHub Actions

[frankischilling]

Part of #13

What to build

Publish the checked-in wiki/ content to the GitHub wiki through GitHub Actions. A push to the approved branch should validate the wiki tree and synchronize it without leaving partial, stale, or unreviewed pages online.

Acceptance criteria

• Add a workflow that validates wiki filenames, links, and required pages before publication.
• Publish only from the approved branch and event, with the minimum required GitHub permissions.
• Synchronize additions, updates, renames, and intentional removals from wiki/ to the GitHub wiki.
• Prevent partial publication when validation or push fails.
• Avoid workflow loops and unrelated repository changes.
• Document authentication, permissions, manual recovery, and local validation.
• Prove the workflow against a test change and confirm the GitHub wiki matches the repository.

Blocked by

• Bootstrap Cupid OS with a self-hosting Cupid toolchain #13
• Consolidate user and developer documentation before merge #39

This work starts after documentation consolidation and must finish before the bootstrap branch merges to main.