* docs: fix API Reference OpenAPI sources and redirects; clarify training data usage; add Mermaid diagram; correct CLI usage and notes
* docs(mintlify): use explicit openapi {source, directory} with absolute paths to fix branch deployment routing
* docs(mintlify): add explicit endpoint MDX pages and include in nav; keep OpenAPI auto-gen as fallback
* docs(mintlify): remove OpenAPI Endpoints groups; add localized MDX endpoint pages for pt-BR and ko
