feat: add CentralRepoOps docs and first example

[mnkiefer]

• Adds new pattern "CentralRepoOps", which describes how to operate and roll out changes across multiple repositories from a single private control repository.

/cc @pelikhan

[Copilot]

Pull request overview

This PR introduces a new documentation pattern called "CentralRepoOps" that describes how to orchestrate and roll out changes across multiple repositories from a single private control repository. This is a specialized deployment variant of MultiRepoOps focusing on centralized governance and large-scale operations.

Changes:

• Adds comprehensive documentation for the CentralRepoOps pattern including use cases, benefits, and implementation details
• Provides a practical Dependabot rollout example demonstrating the orchestrator/worker pattern
• Documents authentication requirements and best practices for multi-repository operations

Comments suppressed due to low confidence (2)

docs/src/content/docs/patterns/centralrepoops.mdx:81

• The description "that will run in each target repository" is misleading. According to the safe-outputs documentation, dispatch-workflow only works within the same repository (same-repo only). This means the worker workflow must be created in the central repository alongside the orchestrator, not in each target repository. The worker then uses the checkout action and target-repo parameters in safe-outputs to operate on target repositories. Consider changing this to: "Next, create the worker workflow .github/workflows/dependabot-rollout.md in the same central repository:"

Next, create the worker workflow `.github/workflows/dependabot-rollout.md` that will run in each target repository:

docs/src/content/docs/patterns/centralrepoops.mdx:39

• Remove trailing whitespace at the end of this line.

a small subset. 

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[mnkiefer]

@pelikhan It's ready! 🎉 Leaving it out of the TOC for now and not cross referencing it anywhere until we have iterated on it, done more testing, etc.