Inventory as code

[wtgodbe]

Ported from an internal PR

Microsoft Reviewers: Open in CodeFlow

[Copilot]

Pull Request Overview

This PR introduces an inventory configuration file to define service metadata and routing information in a structured format. The addition establishes infrastructure for managing service ownership and routing paths systematically.

• Adds es-metadata.yml configuration file with service metadata schema
• Defines service ownership through accountable owners and routing paths

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}