Add OpenAPI Breaking Change Checker

[MartinGryner]

Summary

Adds OpenAPI Breaking Change Checker, a released browser-based tool for comparing Swagger 2.0 and OpenAPI 3.0 or 3.1 descriptions locally.

Submission fit

• The live tool is immediately testable and includes sample descriptions.
• It classifies likely consumer-breaking, review-needed, and normally compatible changes.
• It accepts JSON and YAML, resolves internal JSON Pointer references, and exports Markdown reports.
• Source descriptions stay in the browser; they are not uploaded.
• The UI explicitly presents the result as a heuristic review aid rather than proof of compatibility.

Disclosure

I am the developer. The tool is newly released, so I do not yet have package-download or public-repository adoption metrics to cite.

[netlify]

👷 Deploy request for openapi-dot-tools pending review.

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