oav: Azure OpenAPI Validation Tools

oav (openapi-validation-tools) is a CLI and library for validating Azure REST API specifications written in OpenAPI 2.0 (Swagger) format. Current stable version: 4.0.4. Release cadence is periodic, driven by Azure SDK tooling needs. Key differentiators: it provides semantic validation of spec structures, model validation for request/response examples, traffic validation against recordings, and example quality checks. Built specifically for Azure spec conformance, it supports x-ms-examples and integrates with Azure test-proxy recordings. Requires Node.js >=18, ships TypeScript types, and is primarily used in CI/CD pipelines for Azure SDK repos.