Expand OpenAPI response schemas in reference docs

[muxx]

Summary

• expand object fields from array item schemas in generated OpenAPI Markdown
• replace narrow Markdown tables with a responsive field and parameter list format
• add required, stable operation summaries to the reference route contract
• validate every published array response against its generated field documentation

Verification

• deterministic make generate
• Black and repository formatting checks
• lint, type checks, and unit tests
• release artifact build, validation, and installation checks
• downstream docs refs:sync, reference tests, and full VitePress build